60km (37 miles) W of Stockholm
On one of the precious few sunny Stockholm summer days, we would suggest leaving the city altogether -- by boat -- for Mariefred ("Marie's Place") and Gripsholms Slott. Mariefred, an idyllic little town painted in pastels, invites wandering, but it is really the gateway to Gripsholms, constructed as a fortress for King Gustav Vasa in 1537 and one of the best-preserved castles in Sweden.
To the south of town, Gripsholms Slott eats up a small island in Lake Mälaren with its massive structures, including four round brick towers and two courtyards. This castle was often used by royals to stash bothersome fellow royals. Queen Hedvig Eleonora, reportedly a busybody interfering in politics, was banished here after her husband's death. The son of Gustav Vasa, King Erik XIV, exiled his brother Johan here.
There are worse places to have been banished. Today, you can visit three floors filled with antiques and objets d'art collected over a period of 4 centuries. The castle also houses a national portrait gallery of Sweden, with paintings that range from the great Gustav Vasa himself to today's ruling King and Queen.
During the reign of the 18th-century "actor-king," Gustav III, the Gripsholm theater was erected here. A ham actor, the king cast himself as the star in both comedy and drama. It is one of the best-preserved theaters of its era in Sweden, though not as magnificent as the Drottningholm Theater.
Gripsholm Castle is 68km (42 miles) southwest of Stockholm. By car, follow E20 south; you can drive right to the castle parking lot. To get to Gripsholm Castle, take the train from Stockholm central to Läggesta. From Läggesta, catch a bus to the center of Mariefred. Better yet, boats leave from mid-May to September at 10am from Klara Mälarstrand Pier (250SEK/$50/£25 round-trip) in Stockholm. The castle is a 10-minute walk from the center of Mariefred.
Even though Gripsholm (tel. 0159/101-94; www.royalcourt.se) was last occupied by royalty (Charles XV) in 1864, it's still a royal castle. It's open May 15 to September 15 daily 10am to 4pm; September 16 to May 14 Saturday and Sunday from noon to 3pm, and closed December 21 to January 1. Admission is 70SEK ($14/£7) for adults, 35SEK ($7/£3.50) ages 7 to 18, free for children 7 and under.