Since Sept. 11 it's highly guarded, but it offers tours every 15 mins. to the inside of Independence Hall. The furniture displayed on the first floor is not authentic because British troops burned the originals for firewood. A draft of the original Constitution is on permanent display.
Erected as the Pennsylvania State House, it was restored in 1830 and again in 1950. Today, it more closely resembles its original 1776 appearance, when the Declaration of Independence was adopted.
You get to visit a few different rooms, ie, a court, an assembly room, etc. and though the interior is rather modest, it still retains a dignified air.
Across from the hall sits the Liberty Bell in its own pavillion. The original bell was ordered from an English foundry in 1751 to commemorate the 50-year anniversary of William Penn's 1701 Charter, which spoke of the rights and freedoms of all people. Its most fateful ringing, in the steeple of the State House (now Independence Hall), was on July 8, 1776, when it summoned citizens to hear the first public reading of the Declaration of Independence.
That famous crack, widely attributed to flaws in its casting and caused by a stroke of the clapper, grew bigger every time it was rung. In 1846, the Liberty Bell was moved to Independence Hall; the pavilion opened in 1976, and will be replaced by one next to the new Independence Visitor Center in late 2002-early 2003.
And across market street is the visitor's center which gives out free info on things to see and do.
While I was there they had a lights and sound show going on at night touring center city's main buildings, but don't know if that's still going on. You can also take a tour on a trolley if walking is not your thing.