Bomarsund

Bomarsund is the ruin of the fortress the Russian empire built on Åland's eastern shore to guard its western frontier, a great horseshoe of granite blocks meant to hold a garrison of thousands. It was never finished. A British and French fleet shelled it into surrender during the Crimean War, blew it up, and the treaty that followed left the islands demilitarised, as they still are. The walls lie open and free to wander. Two tower ruins stand on the hills behind, a visitor centre explains the siege, and the garrison's cemeteries lie across the strait on Prästö.