Kastelholm Castle built
1400 CE.
Shown on the map at 60.233°, 20.081°.
Kastelholm Castle (Swedish: Kastelholms slott, Finnish: Kastelholman linna) is a medieval castle built by the Swedes in the late 14th century. It is located near Road 2 in the municipality of Sund in Åland, Finland, about 25 kilometres (16 mi) northeast of Mariehamn, overlooking a fjord near the village of Kastelholm. Kastelholm is one of five surviving medieval castles in Finland considered architecturally significant, along with Hämeenlinna, Olavinlinna, Raseborg, and Turku. Originally built on a small island surrounded by water-filled moats, it served both military and administrative functions. In the 15th and 16th centuries, it was an important stronghold held by nobles, feudal lords, and kings. Damaged during the 1599 civil war and later gutted by fire in 1745, the castle fell into ruin but was partially restored in the 20th century. Since the 1990s, it has been a museum and a key cultural site in Åland.
Text from the Wikipedia article Kastelholm Castle, licensed CC BY-SA 4.0.