Monticello was Thomas Jefferson's mountaintop estate, located in the Southwest Mountains of Virginia. A French nobleman once noted that Jefferson had placed his house, as well as his mind, "on an elevated situation, from which he might contemplate the universe." Monticello is featured on the back of the U.S. nickel and some versions of the $2 bill. It is now operated as a museum and educational institution and is the only personal residence in the United States to be designated a World Heritage site by the United Nations Educational, Scientific and Cultural Organisation.