The Prospect House (also known as the Lingan-Templeman House) located at 3508 Prospect Street, NW in the Georgetown neighborhood of Washington, D.C. Built in 1788, the home is an example of Georgian architecture. It was designed by William Thornton, architect of the United States Capitol. President John Adams visited the residence and Gilbert du Motier, marquis de Lafayette was a house guest. Notable previous owners include Secretary of Defense James Forrestal. Prospect House is listed on the National Register of Historic Places and is a contributing property to the Georgetown Historic District.