Virginia, officially the Commonwealth of Virginia, is a U.S. state located in the South Atlantic region of the United States. Virginia is nicknamed the "Old Dominion" and sometimes the "Mother of Presidents" after the eight U.S. presidents born there. The geography and climate of the Commonwealth are shaped by the Blue Ridge Mountains and the Chesapeake Bay, which provide habitat for much of its flora and fauna. The capital of the Commonwealth is Richmond; and Virginia Beach is the most populous city. Fairfax County is the most populous political subdivision. The Commonwealth's population is over eight million.