Nassau Hall is the oldest building at Princeton University, built in 1756. It was the largest academic building in the American colonies at the time and served multiple functions including classrooms, library, chapel, and student housing. During the American Revolutionary War, it was occupied by both British and American forces and was the site of the Battle of Princeton in 1777. In 1783, Nassau Hall temporarily served as the capital of the United States and housed the Continental Congress. 
The building was designed by Robert Smith with renovations by notable architects Benjamin Latrobe and John Notman after fires in 1802 and 1855. Its thick sandstone walls helped it survive damage through its long history. It is also a National Historic Landmark due to its historical significance
 
interesting fact...
The tigers which guard the door above a relatively modern being erected in 1910. Originally they were a pair of bronzed lion statues given as a gift from the Princeton University Class of 1879 but became worn over time