This amazing house is known as the Knight-Wheeler Mansion and sits a few miles outside of Brownsville, PA on the Old National Pike (Route 40). It was actually two houses in one. The original stone section in the back that is now crumbled, was built back in the late 1700's by Charles Wheeler for Jonathan Knight. According to a 1955 article in the Washington Reporter, Knight was a “civil engineer who built the National Pike throughout most of Washington County and the first chief engineer of the Baltimore and Ohio Railroad.” The Second Empire style front section was added by Oliver K. Taylor around 1880.
Most people would never see this house as you pass by on the highway. It is hidden from view in dense vegetation. From what I can tell, the house was last occupied up until the early 80's and it's been decaying ever since.