Fodor's Expert Review Dulwich Picture Gallery
Designed by Sir John Soane, Dulwich (pronounced dull-ich) Picture Gallery was the world's first purpose-built art museum when it opened in 1811 (the recent extension was designed by Rick Mather). The permanent collection of more than 600 paintings includes landmark works by Old Masters such as Rembrandt, van Dyck, Rubens, Poussin, and Gainsborough. The museum also hosts three or so major temporary exhibitions each year devoted to more contemporary artists like Helen Frankenthaler. Check the website for its schedule of family activities; there's a lovely café here, too.
While you're in the area, take a short wander and you'll find a handful of charming clothing and crafts stores and the well-manicured Dulwich Park, which has lakeside walks and a fine display of rhododendrons in late May. Development in Dulwich Village is tightly controlled, so it feels a bit like a time capsule, with old-fashioned street signs and handsome 18th-century houses on the main street.