Federal Hall National Memorial 
26 Wall St., 212-825-6990, Financial District, Manhattan
One of the most venerable spots in Manhattan, Federal Hall was, literally, the foundation upon which the nation and its three branches of government were built. It served as the original US Capitol Building and housed the first Congress, Supreme Court and Executive Branch offices. This is where the first session of Congress took place in 1789, and it's where George Washington took his oath of office. (Visitors can view the Bible Washington used during his inauguration and the spot where he stood during his swearing-in.) It was here, too, that the Bill of Rights was passed. Although not the original structure, the current building—built as the US Customs House in 1842—is now a national museum and a memorial housing noteworthy displays and seasonal exhibitions. A bronze statue of Washington, erected in 1883, greets guests as they ascend the steps. Admission is free.