57.3745°N, 18.6175°E.
Alskog Trojaborg is a prehistoric or medieval stone-formation labyrinth in Gotland Island, Sweden. The design is a classical 15circuit layout with 15 circuits, 16 walls, approximately 18 metres in diameter, built of stone. Documented age: 1860s (built by local schoolteacher) (1860s (built by local schoolteacher)). Current condition: restored. A 16-wall triple-angle classical labyrinth in woodland 350m northeast of Alskog Church, built in the 1860s by a Mr. Lindgren and restored in 2015 by the local community. Documentation sources: Saward 2003, Gotland Trojaborgs PDF. Listed in the surveyed catalogue as one node in a larger global registry of the same single design.
The labyrinth is one of several hundred sites of this type catalogued globally; each preserves the same unicursal walking-pattern with regional variation in scale, material, and date.