The western front of the United States Capitol. The Capitol serves as the seat of government for the United States Congress, the legislative branch of the U.S. federal government. It is located in Washington, D.C., on top of Capitol Hill at the east end of the National Mall. The building is marked by its central dome above a rotunda and two wings. It is an exemplar of the Neoclassical architecture style. Image File:Capitol Building Full View.jpg from Noclip and kindly released into the public domain.