The village's impressive castle was built on the site of an earlier Romanesque fort, of which the only surviving bits are the tall square tower, and fragments of a rotunda and palace. Its present late-Gothic look dates from the 14th century. Visits are normally by guided tour, though you can opt to walk around on your own with English text. Exhibitions include Gothic murals, a gruesome tableaux of torture instruments, and two rooms full of luscious locally produced ceramics.
The castle, surrounded by water on three sides and nearly impregnable, has played an important role in Bohemian history. Young Wenceslas, the future Holy Roman Emperor Charles IV, was imprisoned here around the year 1320 as a child. He apparently enjoyed visiting the castle, though, later in life. From 1788 until 1947, the castle was used (and abused) as a local prison.