11 km/7 mi along the main road from Zealand lies the capital of Møn island, Stege. The town grew up around a castle built by Valdemar I about 1175 as a defense against enemy forces from the east. In the 15th C. it was surrounded by a wall and a moat; only one of the three town gates, Mølleporten (Mill Gate), has been preserved; apart from the
one at Fåborg it is the only surviving medieval gate in Denmark.
St. Hans' Church, built about 1250 in Romanesque style, was enlarged by the addition of a three-aisled choir in the 15th C.; it has rich fresco decoration in the choir and nave.
In Møn Museum can be seen geological and archaeological finds, photos, costumes, silverware and seamen's chests.