Historic preservation (US), built heritage preservation or built heritage conservation (UK) is an endeavor that seeks to preserve, conserve and protect buildings, objects, landscapes or other artifacts of historical significance. It is a philosophical concept that became popular in the twentieth century, which maintains that cities as products of centuries' development should be obligated to protect their patrimonial legacy. The term refers specifically to the preservation of the built environment, and not to preservation of, for example, primeval forests or wilderness.

Washington's Headquarters State Historic Site, also called Hasbrouck House, is located in Newburgh, New York, United States, overlooking the Hudson River. George Washington and his staff were headquartered in the house while commanding the Continental Army during the final year and a half of the American Revolutionary War; at 16 months and 19 days it was his longest tenure at any of his headquarters during the war.