Haapsalu’s crumbling heart is its bishop’s castle, which was western Estonia’s centre of command from the 13th to the 16th centuries but now stands in partial, very picturesque ruins. A turreted tower, most of the outer wall and some of the moat still remain. Entry to the grounds is free year-round, but a ticket is required to enter the castle proper, where there’s a museum devoted to its history, including some creepy tunnels and dramatically displayed medieval weaponry.
Accessed from within the museum is the striking Dome Church (properly, St Nicholas’ Cathedral), built in a mix of the Romanesque and Gothic styles, with three inner domes. It’s the largest such structure in the Baltics and its phenomenal acoustics means concerts are regularly held here. Inside the church, keep your eyes peeled for the ghost of the White Lady.
In summer, the park within the outer walls is used for concerts. There’s a wonderful children’s playground complete with a pirate ship, and a viewing platform within one of the towers. You can also try your hand at archery just outside the main gate (€5 for 10 arrows).