Prague Castle

Perched above the Vltava since the 9th century, Prague Castle is less a single building than a walled town: courtyards, gardens, a cathedral, a former monastery, and a lane of miniature medieval houses all inside one perimeter.

Give yourself at least half a day. St. Vitus Cathedral alone rewards slow looking — its stained glass includes a window designed by Art Nouveau painter Alphonse Mucha.

Arrive right at opening or after 3pm to avoid the worst of the tour-group crush, especially in summer.