Location: 5 km (3 mi) South of Gudhjem, Bornholm island
Dedicated: St. Laurentius (St. Lawrence, St. Lars)
Østerlars Church (Østerlars Kirke or Østerlars Rundkirke) is the largest and likely the oldest of the four famous round churches on the Danish island of Bornholm in the Baltic Sea. It stands just north of the village of Østerlars, about 5 km south of Gudhjem.
Construction and Early History (12th Century)
The church was
built around 1150–1160 during the Romanesque period, making it one
of Denmark’s oldest surviving churches of that style. Coins dated
1157 found in the floor provide key evidence for this dating.
It
is dedicated to Saint Lawrence (Danish: Lars or Laurentius), and its
name evolved from Laurentii Kirke (or Larsker) to Østerlars (“East
Lars”) to distinguish it from another nearby church dedicated to St.
Nicholas.
Bornholm limestone and locally sourced fieldstone form
the foundations and walls. The structure features a distinctive
round nave (external diameter about 16 meters), an oval chancel, and
a small apse. A massive hollow central pillar (about 6 meters wide)
supports the roof and contains a small internal room called “the
oven.”
The double-arched apse shows similarities to Lund
Cathedral in Sweden, reflecting architectural influences from the
period.
Purpose: Church and Fortress
Like the other
Bornholm round churches (Nyker, Nylars, and Olsker), Østerlars
served a dual purpose: as a place of worship and a fortified refuge.
Bornholm’s strategic location on Baltic trade routes made it
vulnerable to pirates (Wendish pirates were a notable threat) and
political conflicts.
Key defensive features include:
Extremely thick walls (over 2 meters) built with a double-wall
technique filled with soil and gravel.
Originally no roof (or a
lower one), allowing the upper level to function as an open shooting
gallery or watchman’s gallery.
Narrow Romanesque windows (later
enlarged).
Buttresses added in the 16th century for extra
support.
A commanding position with views over the surrounding
countryside.
A heavy bar on the main door for securing the
entrance.
There is no archaeological evidence of actual
attacks on the church, suggesting it successfully deterred threats
or served primarily as a safe haven for locals and their valuables.
Theories on the round design include:
Fortification — The
circular shape offered better defense against sieges (no corners to
breach).
Knights Templar influence — Some link it to the Templars
due to round churches they built (modeled on the Church of the Holy
Sepulchre in Jerusalem) and connections via Archbishop Eskil of Lund
and Bernard of Clairvaux. However, this remains speculative.
Observatory or symbolic — Less common theories suggest astronomical
or cosmic symbolism.
A separate bell tower (originally a gate
tower and entrance) stands in the churchyard. It houses bells from
the 1640s and 1680s. Two runestones are associated with the site:
one from c. 1070 outside and one from c. 1100 in the porch,
evidencing earlier Viking-era Christian activity on Bornholm.
Later Modifications
Roof — The current conical roof (with
wooden shingles of split Bornholm oak, regularly tarred) dates
primarily to 1744, though similar roofs appear in 17th-century
drawings. It was added once the defensive role diminished.
Windows and buttresses — Enlarged and added in the 16th century.
Porch — Added in 1870.
Modern Era and Significance
Østerlars remains an active parish church while serving as a major
tourist attraction and national cultural heritage site. It
symbolizes Bornholm’s medieval history and unique architecture.
Visitors can climb to the upper levels for panoramic views.
The
church and its surroundings reflect layers of history: prehistoric,
Iron Age, Viking (runestones), and medieval Christian fortifications
amid Baltic power struggles. It stands as a testament to the
ingenuity of 12th-century builders who created multifunctional
structures that have endured for over 850 years.
Overall Layout and Dimensions
Structure: The church consists of
three main parts: a round nave, an oval chancel (choir), and a smaller
semicircular apse. It rises in three storeys.
Nave: The round nave
has an external diameter of about 16 meters. In the center stands a
massive, hollow circular pillar approximately 6 meters wide, which is a
defining architectural feature.
Walls: The outer walls are
exceptionally thick—up to 2 meters—built in a double-wall technique with
fieldstone (local granite and limestone) on the outside, a cavity filled
with soil, gravel, and rubble for stability and insulation, and an inner
face. Foundations rest on Bornholm limestone.
Height and Levels:
Originally designed with defensive capabilities across three storeys.
The upper levels provided refuge and fighting platforms.
Exterior
Architecture
The exterior is striking for its robust, whitewashed
appearance (common in Danish churches) and conical roof:
Roof: A
tall, dark, wooden-shingled conical roof (current version from 1744,
replacing earlier ones; not original). The church originally may not
have had a full roof or had a lower outer wall for an open defensive
gallery/walkway around the top.
Defensive Elements: Thick walls,
small original Romanesque windows (later enlarged post-Reformation for
light), and a design allowing movement around the outer passage. It
commanded views of the surrounding countryside for surveillance against
pirates and invaders (Wendish or other seafaring threats common in the
region).
Additions:
Separate bell tower (campanile) in the
churchyard, originally serving as the entrance/gate tower.
Porch
added in 1870.
External buttress pillars added in the 16th century to
support the outer wall.
Materials: Primarily local stone, emphasizing
its fortress-like solidity.
The building blends ecclesiastical and
military architecture, typical of Bornholm’s round churches built in a
turbulent era.
Interior Architecture
The interior is spacious
yet intimate due to the circular form and central pillar:
Central
Pillar: The hollow central column supports the roof and creates a
dramatic focal point. It contains a small internal room ("oven")
accessible via an opening. This pillar, combined with arches radiating
outward, divides the space into a central area and ambulatory-like
passages.
Arches and Openings: Massive arches connect the central
pillar to the outer walls, creating a sense of strength and openness.
Stone steps in the chancel lead to upper levels.
Gallery and Upper
Storeys: A wooden gallery runs around parts of the interior; the second
and third storeys were used defensively. Narrow spiral stairs built
within the thick walls provide access (a notable engineering feature).
Chancel and Apse: The oval chancel leads to a double-arched apse,
showing similarities to Lund Cathedral in Sweden.
Murals/Frescoes:
One of the highlights is the well-preserved Romanesque frescoes (some of
the oldest and finest on Bornholm), uncovered in the 19th century and
restored in 1958. They depict biblical scenes, including the life of
Christ, the Nativity, apocalyptic/Judgement Day motifs, and saints.
These are located on the upper walls and arches, adding vibrant color
and narrative depth.
Other Interior Features:
Original
baptismal font.
Later additions like curved pews, organ, and a double
altarpiece (painted by local artist Poul Hom in 1973).
Exposed wooden
roof truss structure visible when climbing to the upper levels.
Historical and Functional Context
Built around 1150–1160 (coins dated
1157 support this), the church was dedicated to Saint Lawrence (Lars).
It served dual purposes: worship for the local community and a
refuge/fortress during attacks. This explains the round shape (better
defense, no corners to breach), thick walls, limited early windows, and
multi-level design.
Modifications over centuries (e.g., roof,
windows, supports) adapted it from a fortified structure to a primarily
religious building while preserving its medieval character.