The 'birthplace of American government,' this modest early 18th-century Georgian building is where delegates from the 13 colonies met to approve the Declaration of Independence on July 4, 1776. Expect a line out the door and around the block for this one – it's the prime attraction in a city packed with history.
The entrance is via the security screening area in the east wing on the corner of Chestnut and 5th Sts. Get free advance tickets and times for the next available tour at the nearby Independence Visitor Center or reserve online (fee $1.50). Budget for at least an hour wait in peak summer months.