One of the largest castle ruins in Central Europe: four hectares of walls, courtyards and towers on a travertine hill that commands the Spiš plain for miles. No army ever took it — a fire destroyed it in 1780 — so what survives is the complete military plan, readable as you walk it. From the Romanesque keep you get the Tatras on one side and the town of Spišské Podhradie on the other.