Here are a few links to virtual tours of some famous buildings:

Washington, D.C.:

Library of Congress - Thomas Jefferson Building Tour

Smithsonian National Museum of Natural History

The Kennedy Center

U.S. Botanic Garden

U.S. Capitol (Senate) Virtual Tour

U.S. Supreme Court Building



Martin Luther King, Jr. Birth home



Harvard College



National Museum of the U.S. Air Force



Gettysburg National Military Park



George Washington's Mount Vernon

Monticello - Charlottesville, VA: Designed and built by Thomas Jefferson