Riga is the obvious starting point and deserves at least two or three days. The medieval Old Town is a UNESCO World Heritage Site, but the more distinctive draw is the Art Nouveau architecture that covers whole neighbourhoods in astonishing decorative stonework. The Central Market — housed in five former German zeppelin hangars — is one of the best food markets in Europe.
The Gauja National Park is the country's finest natural landscape, a forested river valley with sandstone cliffs, caves, and a string of medieval castles. The towns of Sigulda and Cesis are the best bases; both are easily reached by train from Riga. Sigulda has an operating bobsled track and a dramatic cable car crossing the valley; Cesis has a well-preserved medieval castle and a charming old town.
Jurmala is a long beach resort running along the Gulf of Riga, 25 minutes from the capital by train. It's been popular with city dwellers since the 19th century, and the rambling wooden villas in the pine forests give it a distinctive, faded-elegant atmosphere. In summer it fills up; off-season it has a pleasant melancholy.
Liepaja on the west coast is worth the three-hour trip from Riga for its beaches, the extraordinary Holy Trinity Church organ (7,000 pipes, reportedly the world's largest surviving historic unreconstructed organ), and the eerie Karosta district — a tsarist-era naval base that was later used by the Soviets and is now partly open to visitors including a functioning prison hostel.
Daugavpils in the southeast is Latvia's second city and largely Russian-speaking. The massive 19th-century Daugavpils Fortress has been partly restored and now houses the Mark Rothko Art Centre — a genuinely good museum dedicated to the abstract expressionist painter who was born here.