Downtown Austin is the natural starting point for seeing the city's sights, and is home to many of them, including the state capitol. Its boundaries are generally regarded as being I-35 to the east, Lamar Boulevard to the west, UT to the north, and the river to the south. It's relatively compact and well served by buses and the free 'Dillo trolleys, so if you're primarily interested in touring downtown, you won't need a car. The capitol complex is the most visible landmark, of course, but most of the important museums (save for the Blanton) and many historic buildings are between the capitol and the river.
Areas within downtown are the Market District, the Warehouse District, Second Street District, Congress District, 6th Street, and the Red River District.
Some of these districts are so distinct that we've given them their own neighborhood section within this chapter for categories like shopping, dining, and lodging.
For the sake of soaking up the atmosphere and getting a sense of the city, we highly recommend walking the ten blocks up Congress Avenue between 11th Street and the bridge, in either direction. And at some point, walk down 6th Street between Congress Avenue and I-35.