Denmark · Ruin
Lilleborg
Lilleborg is a ruined 12th-century fortress located on a rocky hill in the Almindingen forest on Bornholm, Denmark, originally surrounded by the lake Borresø. Constructed as a compact royal stronghold, its principal surviving features are the oval curtain wall and the large square tower that defended the entrance.
First raised
1190
Its prime
1160
Today
Ruin
As it stood in 1160
What Lilleborg looked like in its prime.
Lilleborg in its prime (c.1160) occupied a 16-metre rocky island in Borresø, an oval stone plateau ringed by a low curtain wall that follows the cliff edge. A single large square tower about 9.5 metres across guarded the south entrance; masonry of coarse local stone with walls roughly 2.4 metres thick dominated the entrance. The enclosed interior measured approximately 76 by 41 metres and was reached by a wooden bridge and steep approach from the south.
Its story
The story of Lilleborg.
Lilleborg was raised in the 12th century on a rocky hill sixteen metres high in the Almindingen forest at the centre of Bornholm — at the time completely surrounded by the lake Borresø, and reached by a wooden bridge and a steep path. King Sweyn III wanted a seat of power of his own on the remaining fourth of the island, and of Denmark's 12th-century fortresses Lilleborg most closely resembles those of Saxon architectural style.
A square tower 9.5 metres on a side, with walls 2.4 metres thick, protected the entrance to a courtyard some 76 by 41 metres inside a curtain wall following the cliff tops. The fortress appears to have burnt down in 1259, when Prince Jaromar of Rügen stormed and destroyed the "king's stronghold" on Bornholm; once its defences were obsolete its stones were reused elsewhere, and restoration work ran from 2006 to 2011.
The hill was fortified long before the medieval castle: in 2025 researchers from the National Museum of Denmark and Bornholms Museum concluded that some form of fortification already stood on the site in the 4th century, remains of the Iron Age work having been discovered in 2010.
Step inside
6 places to explore in 1160.
The record describes 6 distinct spots at Lilleborg — including 1 interior: central courtyard of the oval plateau. Create your own photoreal reconstruction and walk through every one — more scenes means more rooms, more angles, and more of the place to stand in.
Create History
Recreate Lilleborg with AI to explore it.
The artist rebuilds it as it stood in 1160 — a photoreal walk that belongs to you alone. Pay with coins, no subscription needed.
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