Belvoir was the plantation and estate of colonial Virginia's prominent William Fairfax family. Operated with the forced labor of enslaved people, it sat on the west bank of the Potomac River in Fairfax County, Virginia, at the present site of Fort Belvoir. The main house — called Belvoir Manor or Belvoir Mansion — burned in 1783 and was destroyed during the War of 1812. The site has been listed on the National Register of Historic Places since 1973 as "Belvoir Mansion Ruins and the Fairfax Grave."