The Goose Tower (Gåsetårnet) is the last standing tower of Vordingborg Castle and the town's most recognisable landmark. It rises 26 metres above the castle ruins and retains its original 14th-century form, topped by a golden weathervane in the shape of a goose — Valdemar Atterdag's mocking riposte to the Hanseatic merchants who traded through his kingdom. When the castle was otherwise demolished in pieces over the centuries to provide stone for other buildings, the tower survived simply because it was too useful as a navigation point for ships in the Storstrøm.
The tower became Denmark's first protected historic monument in 1808, when it was transferred to the national trust. You can climb it for a fine view over the town and the water, though the internal staircase is steep. The surrounding ruins — remnants of curtain walls, foundations, and scattered stonework — are freely accessible and give a sense of the fortress's original scale, which once stretched over a significant part of the old town.