The Governor's Mansion, the most historic house in Texas, sits on a beautifully landscaped city block in Austin near the Capitol building. Built in 1856, it is the oldest continuously occupied executive residence west of the Mississippi. The building has been designated a National Historic Landmark. Free guided tours of the Texas Governor's Mansion are available Wednesdays, Thursdays, Fridays, and select Saturdays, from 2:00 p.M. To 4:00 p.M. Tours last 30 minutes and are subject to availability. Reservations are required for tours and must be made at least one week in advance. There are no walk-up tours.