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83
VI/1/2015
INTERDISCIPLINARIA ARCHAEOLOGICA
NATURAL SCIENCES IN ARCHAEOLOGY
homepage: http://www.iansa.eu
Archaeological and Geophysical Investigation and 3D Visualization at the
Jánský Vrch Castle in Javorník (Czech Republic)
Hana Dehnerová
a
, Jan Martínek
b
, Martin Moník
c*
, Pavel Šlézar
a
a
National Heritage Institute, Horní náměstí 25, 771 11 Olomouc, Czech Republic
b
Transport Research Centre, Research institute, Branch offce Olomouc, Wellnerova 3, 779 00 Olomouc, Czech Republic
c
Department of Geology, Faculty of Science, Palacky University, 17. listopadu 12, 771 46, Olomouc, Czech Republic
1. Introduction
The Jánský Vrch chateau, originally a gothic castle, is a
dominant feature of Javorník town (Jeseník district, Olomouc
region, Czech Republic; Figure 1). It was built on a rock
spur reaching from the Rychlebské hory Mountains into the
Vidnava Lowland. This elevated point controls the area to
the north, east and south-east; also visible from the spur are
the Polish towns of Paczków and Otmuchów. New pieces
of knowledge were acquired between 2002 and 2006 by
archaeological excavation and supplemented by geophysical
prospecting in 2013 and 2014 that verifed the position and
nature of castle’s historical fortifcations and buildings. This
prospecting was accompanied in 2013 by 3D laser scanning
at the glacis south of the castle where two structures of
unknown origin, probably for fortifcation, had also been
identifed (Anonymous 1934).
1.1 History of the Javorník castle/chateaux
In the course of the second
half of the 13
th
century, Javorník
village, along with a stronghold and the St. Cross church,
was founded in the lowland around Javorník Creek in Silesia.
This took place during the course of the High Middle Ages
colonization process directed by Otmuchów castle, though
infuenced, however, by the long-lasting territorial conficts
between the diocese and the princes of Wrocław. The frst
written record of the village comes from the register of assets
of the Wrocław diocese from 1290. The aforementioned
stronghold was erected at the strategic crossroads of roads
connecting Moravia and Silesia and remained in function
until the frst half of the 15
th
century, when it was probably
destroyed as the Hussites moved towards the principality of
Nisa (Brachtl, Dohnal 1992).
Historical records indicate that Javorník village was
commanded around the end of the 13
th
and start of the
14
th
centuries by the duke Bolko I of Svídnice who had a
castle built to control both land border and roads connecting
the Kłodzko Lowland with the Nisa watershed. In a
Volume VI ● Issue 1/2015 ● Pages 83–92
*Corresponding author. E-mail: martin.monik@gmail.com
ARTICLE INFO
Article history:
Received: 1
st
December 2014
Accepted: 2
nd
June 2015
Keywords:
Middle Ages
castle
Silesia
ERT
GPR
3D laser scanning
ABSTRACT
An archaeological investigation realized between 2002 and 2012 has re-interpreted the construction
phases and spatial organization of the Javorník Castle in Czech Silesia. Its frst phase, dating to the
beginning of the 14
th
century, consisted of a bergfried-type castle with a rounded fortifcation ditch.
This fortifcation was re-built at the end of the 15
th
and start of the16
th
centuries when the castle
was divided into upper and lower portions. The Modern Age has seen a complex of constructions at
the glacis, pictured also in historical vedutas. Between 2013 and 2014, certain data acquired earlier
by archaeological prospecting and excavations were corroborated by electric resistivity tomography
(ERT) and ground penetrating radar measurement (GPR); moreover an advanced siege fortifcation,
probably related to a Hussite siege of the castle, was identifed by 3D laser scanning south of the castle.
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(Czech Republic)
84
document from 1307, a castle manager is already mentioned
(Kouřil
et al.
2000). After 1348, duke Bolek II of Svídnice
left his part of Javorník to the Bishop Przeclav of Pogarel
and the castle became the property of the Wrocław diocese.
Between 1428 and 1432, the castle was taken and occupied
by the Hussites and partially destroyed after their departure
(for details see Kouřil
et al.
2000).
The actual appearance of the castle is due to several
reconstructions which took place mainly at the end of the
15
th
, and then the beginning of the 16
th
, and during the course
of the 18
th
century. The bishops Jan Roth and Jan Thurzo had
the castle, now called Jánský Vrch (Johannisberg), rebuilt
between the 1480s and 1509 into a Late Gothic castle. Later
Baroque reconstruction took place during the episcopacy
of Filip Gothard Schaffgotsch and a Classicist stairway
was constructed around the 1890s/1900s (the building’s
construction history has been covered by Vítek 2000).
1.2 Overview of archaeological knowledge
Archaeological fnds were made at the site already in the
1930s but a systematic investigation only took place after
1990 in relation to construction history research of the
chateaux (
e.g.
Brachtl 1998; 2000). An archaeological
salvage excavation took place in 2001 and 2002 along with
some sewer reconstruction at the eastern glacis (Figure 2; in
greater detail in Dehnerová, Šlézar 2013).
An up-to-date archaeological investigation has revealed
that the oldest activities at the castle date from the 14
th
century,
which is in accordance with its supposed foundation at the
beginning of the 14
th
century. In the frst phase (14
th
–15
th
century), a castle of a bergfried type was built, fortifed by
a curved ditch (for more details see Dehnerová, Šlézar, in
press). In the northern part of the eastern glacis, outside of
the ditch, buildings connected with the defence of the castle’s
entrance have also been identifed (Figures 2 and 7). A stone
building had stood here, a part of which was unearthed
close to the north-eastern corner of the castle (Figure 7),
and to the north there had stood another wooden and earthen
construction as indicated by a fre destruction layer there.
Signifcant activities from the period of the castle’s
reconstruction around 1500 were also identifed. The
fortifcation ditch had been flled with the debris of destroyed
buildings from around the bergfried, and the terrain, including
the ditch, was covered by a mortar layer. From out of the
ditch, pottery from the end of the 15
th
and start of the 16
th
century was acquired. A new fortifcation 1.4 metres wide
was built later, identifed by excavations made in two places
(Figures 2 and 7) – in the northern part close to the entrance
gate and in the south close to the Classicist house where it
had been supported by a tower (overbuilt later by a Modern
Age wall). During this period, construction modifcations
also took place of the gate building and its vicinity.
In the Modern Age (16
th
–18
th
century), the area of the
eastern glacis was paved over several times, levelled
by further landflls and partially overbuilt by buildings
as indicated by both archaeological investigations and
iconographic sources from the 18
th
century.
After 2002, two major construction works took place in
the castle area, both related to public utilities’ construction.
The related trenches actually confrmed the knowledge
acquired by earlier investigation. They cut into the layers
of Modern Age landflls: in several places remnants of
cobble pavements at a depth of 1.3 metres were identifed.
The rock bed, formed here by amphibolites and gneisses
of the Orlice-Sněžník unit (Žáček 1995), was evidenced
just exceptionally in the farmyard (Figure 7). The oldest
identifed pottery dates from the 14
th
–15
th
centuries, but
comes from secondary contexts. A number of walls were
identifed as well, namely in the northern part of the glacis
where a foundation stone wall 5.15 m in length and 1.2 m
Figure 1.
Location of Jánský Vrch castle
(arrow) in Javorník.
0 500 m
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85
in thickness was unearthed, out of which further walls ran
in an easterly direction (Kaiser, Šlézar 2007). It formed part
of a building with the longer axis oriented in a north-south
direction and had been most likely connected to the stone
corner from the 14
th
century, documented in 2002. Another
stone wall discovered probably formed part of a cellar. It
was unearthed in the eastern vicinity of the castle, stretching
over 11 metres in length (Figure 7). Its eastern face ran in a
N-S direction and two further walls, 5.6 m apart, had been
connected to it perpendicularly. The northern one was 2.2 m,
the southern one 1.5 metres, wide. A stone wall 0.9 m wide
and at least 2 m long, bound by a limey mortar, was also
identifed in the farmyard. Just a Modern Age set of layers
was identifed in its vicinity (Faltýnek 2013).
2. Methods
In 2013, geophysical prospecting was carried out in both the
small courtyard in the lower part of the castle and the eastern
glacis. Both ground penetrating radar (GPR) and electric
resistivity tomography (ERT) were used, specifcally a
SIR3000 GPR device (GSSI Inc., USA) with an antenna with
a frequency of 400 MHz and the geoelectric system ARES
(Gf. Instruments, Czech Republic). The task was to identify
the course of the High Middle Ages fortifcation ditch, the
15
th
to 16
th
century reconstructions of the castle fortifcation,
and possibly other constructions in the eastern glacis. GPR
measurement was realized in parallel lines spaced 0.5 metres
apart, using a “zig-zag” pattern. Terrain disturbances to the
Figure 2.
Javorník, Jánský Vrch –
overview of archaeological activities in the
castle area from 1995 to 2012.
0 25 m
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antenna were minimal as the small courtyard (Figure 7) is
paved and the eastern glacis area is a shortly cut lawn. ERT
was applied as straight line sectioning with the electrodes
spaced at 0.5 metres. Length of the fve realized sections
varied between 15.5 and 39.5 metres.
Measurement results were processed with RADAN
6.5 (GPR) and RES2INV (Geotomo software, Malaysia)
software. Both GPR and ERT methods are frequently used
in geoarchaeological prospecting of medieval constructions
and other stratigraphic units (
e.g.
Campana, Piro 2009;
Tsokas
et al.
2009).
We also focused on the fat area south of the castle
(Figure 3). Behind the medieval ditch, the terrain rises
steeply and turns into a plateau overlooking the entire castle.
This plateau, however, is dotted by terrain bumps. Already
in the 1930s, two of these bumps were recorded in a drawing
and identifed as “Schanzen” (Figure 4; Anonymous 1934).
Thus 3D laser scanning was applied to verify the presence
and course of any fortifcation remnants. Results from the
measurements made it possible to create a digital model of
the terrain (Martínek 2014). The data were acquired by a
private company through ground laser scanning, using the
FARO FOCUS 3D scanner with a reach of 130 metres, a
resolution of <2 mm and scanning speed of 976,000 points
per second. Each point on the surface was characterized
by three coordinates and also by its colour, refecting the
intensity of the received signal. In this way, a cloud of
1,159,214,300 points was acquired, referenced to 5 fxed
Figure 3.
Javorník, Jánský Vrch, view
from NE. The arrow marks the area of 3D
scanning.
Figure 4.
Reconstruction of the medieval
castle area, 1934.
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points situated around the measured area and thus located
in the S-JTSK/BpV cartographic system. A digital elevation
model was then calculated through interpolation using the
ArcGIS 10.1 program (Esri inc., USA).
3. Results
3.1 Geophysics
Two areas were submitted to GPR measurement (Figure 5).
The frst one was the small courtyard where a rectangular
GPR1 Probe 1, the size of 12×3 m, was used. Two anomalies
were identifed here, the frst one indicated by an intense
(“wavy”) microwave signal, the other by a signifcant
concave anomaly. The second GPR measurement (GPR2),
the size of 15×15 m, was made in the eastern glacis. What
became evident here were two linear structures running in an
approximately N–S direction and evidenced also in the ERT
Section 4 (see below).
As for the ERT measurement, six sections (Sections 1–6)
were made in the eastern glacis area (Figure 6), ranging in
length from 15.5 to 39.5 m. Each of them identifed a number
of subsurface anomalies, ranging in values from almost zero
to about 700 Ωm. The depth reached by this kind of ERT
prospecting is dependent on the length of the section and
ranged between 3.5 to 7.5 m. In general, lower positioned
layers and flls showed lower resistivity values, whereas
units close to the surface were usually more resistive.
3.2 Laser scanning
The 3D laser scanning was suitable for the imaging of even
the slightest terrain irregularities within the large areas. The
images acquired through 3D laser scanning on the plateau
south of the castle visualized two irregularly rectangular
Figure 5.
Results of GPR measurement in
the small courtyard (top) and the eastern
glacis (bottom).
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Figure 6.
Six ERT sections executed in the eastern glacis and their interpretation.
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elevations the size of 12×20 and 10×15 m, about 25 m apart
(Figures 8 and 9). Their situation answers to the drawing from
1934 (Figure 4). In contrast to that drawing, further terrain
modifcations became evident thanks to the laser scanning.
4. Discussion
The anomalies identifed through GPR measurement in the
small courtyard answer to a disturbed subsurface of intense
radar signal in the southern part, possibly representing the
flling of a ditch, whereas the concave-like signal (Figure 5)
in the northern part probably represents a wall (
cf.
Herz,
Garisson 1998; Figure 8.10). The existence of High Middle
Ages ditch in these parts was expected as its course had also
been identifed in the area of the fanking tower (Kouřil 2009;
Rychlý, Kolář 2002) and its continuation had been unearthed
in the eastern glacis in the close vicinity of today’s entrance
(Šlézar 2003; Dehnerová, Šlézar 2013).
Two linear structures identifed in the 15×15 m GPR
Probe 2 in the eastern glacis are of unknown function so that
they can be classifed just as “linear structures” (Figure 7).
Their course does not answer to the medieval ditch, they
are, however, parallel to the defensive wall from the 15
th
or 16
th
century. Whether they formed part of the defensive
system or not is, as yet, unclear, as is their age. The eastern
structure is more signifcant: as was also detected by the ERT
measurement (see below).
In ERT sections, the anomalies can be broadly divided into
four principal categories. The frst is a low resistivity signal
Figure 7.
Plan of ERT and GPR
measurements, course of supposed High
Middle Ages fortifcation ditch, different
parts of the castle mentioned in text, and
structures unearthed by archaeological
excavation.
0 25 m
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(0–80 Ωm), identifed just in Section 1 and potentially in
Section 6. It may be supposed that this might be a refection
from the local bedrock, as amphibolites are often rich in
low-resistivity iron-rich minerals, although porosity may be
also responsible for the low resistivity (
e.g.
Philpotts 2003;
Milsom 2003). If the low-resistivity anomaly in Section 1 is
indeed a rock spur, it must have been encircled by the High
Middle Ages defensive ditch just in this place (Figure 7).
The second is a slightly higher resistivity anomaly,
observed in Sections 2–5 (25–120 Ωm). It forms a kind of
heap and can be related to one of the linear anomalies also
identifed in the GPR Probe 2. Its function is unclear. If it
is of artifcial origin, which seems probable, it must have
reached at least a depth of 4.3 m (Figure 6, Section 5) so that
a defensive function can be presumed.
In the course of terrain levelling later on, some heaping of
low-resistivity (about 12–80 Ωm) soil east of this structure
took place as indicated by Sections 4 and 5. Finally, there
are high-resistivity anomalies in practically all ERT sections,
ranging between 200–800 Ωm. These may be related to walls,
and connected with both the buildings and Modern Age
fortifcation lines. In Sections 1 and 6, a continuation of the
15
th
–16
th
century defensive wall, unearthed by archaeological
excavation further to the west, was probably detected, and
walls of buildings from the same period were recorded in
Sections 4 and 5. Walls of unknown age or continuation were
detected in Sections 2 and 3.
As for the High Middle Ages ditch, unearthed in places by
earlier archaeological excavation, this was probably detected
in Section 1 and 5. Its flling is low-resistive (25–50 Ωm)
Figure 8.
Shaded relief acquired by
interpolation of 3D laser scanning. Angle of
exposure: 315°; Z factor: 4.
Figure 9.
Interpolated image of elevations
(A, B) and terrain remnants of a supposed
light fortifcation south of the castle. Angle
of exposure: 315°.
0 60 m
0 30 m
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in Section 5 but high-resistive in Section 1 (up to about
400 Ωm) where it is probably formed by construction debris.
This fnding, however, should be verifed in the future with
ERT sectioning of a larger dimension or by archaeological
excavation. Ditch flling was not detected in Sections 2–4
and 6 as it had been obliterated by younger landflls and
constructions.
The 3D laser scanning of the terrain south of the castle
(Figure 8) not only confrmed visual prospecting undertaken
earlier but also made the shapes recorded in drawing in
1934 and in the contour mapping of 1991 more precise
(Vozda 1991). Most of the recorded irregularities are likely
park tracks and paths. More interesting are less pronounced
terrain irregularities along the edge of the plateau, between
the elevations and the northern edge of the plateau (Figure 9).
These may represent remnants of a lighter fortifcation
of the plateau. Even though the elevations are considered
to be of medieval age in the reconstruction from 1934, it
cannot be excluded that they are Modern Age structures
originating from Romantic era modifcations of the chateaux
gardens (all above the eastern elevation; Figure 9:B). More
probable, however, is that they are of medieval origin. Their
form (including the lines of possible light fortifcation) and
situation close to the ditch in front of the core of the castle
may be related to fortifcation works. Historical records of
the castle’s history indicate the diocese castle was besieged
between 1428 and 1434 by the Hussites. Archaeological
excavation undertaken close to the northern fanking tower in
2001 demonstrated battle activities from around this period,
most probably from the spring of 1428 (Kouřil 2009). It is
quite possible the plateau had been fortifed by this time,
forming either an advanced fortifcation of the castle or the
siege camp of the Hussites. Archaeological excavation is
required to confrm or disprove these possibilities.
5. Conclusion
The frst phase of Javorník castle was constructed at the
beginning of the 14
th
century as a bergfried type with a curved
fortifcation ditch. It was rebuilt in the 15
th
and 16
th
centuries
together with the fortifcation system. In the Modern Age,
new buildings appeared in the glacis, as indicated by
contemporary vedutas. Both GPR and ERT measurements
identifed structures related to the mentioned construction
phases. ERT Sections 1 and 5 probably detected the High
Middle Ages fortifcation ditch, whereas virtually all sections
detected building walls either of unknown age or dating
from the 15
th
to 16
th
centuries. A linear structure, possibly
a fortifcation line of unclear age, was also detected in ERT
Sections 2–5 and GPR Probe 2. From a methodological point
of view, the combination of these two methods proved itself
effective.
Prospecting with 3D laser scanning identifed several
irregularities on the hill south of the castle. Two parallel lines
south of two prominent elevations within the hill represent
either an amplifcation of the medieval castle or a siege
fortifcation related to the Hussite siege of Javorník in the
spring of 1428.
Acknowledgements
This article was written as part of the investigation
“Archaeology 1.2, investigation of archaeological potential
of selected historical areas and objects in the Czech Republic”
supported fnancially by the conceptual development
program (DKRVO) of the Ministry of Culture. Our thanks
are due to Milan Rychlý from the Regional Museum in
Jeseník and Kateřina Danielová from the Cultural Heritage
Service in Kroměříž, the castle manager.
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