National Harbor, in Price George's County, is located along the Potomac River.
Oxon Hill-Glassmanor was a census-designated place (CDP) in Prince George's County, Maryland, for the 1990 and 2000 censuses. 
National Harbor is a development along the Potomac River in Oxon Hill, Prince George's County, Maryland just south of Washington, D.C. near the Woodrow Wilson Bridge. 
