The Piper Aviation Museum exhibits aircraft and aircraft equipment, documents, photographs, and memorabilia related to Piper Aircraft. An eight-room home, the Heisey House, restored to its mid-19th-century appearance, displays Victorian-era collections; it was added to the National Register of Historic Places in 1972 and is home to the Clinton County Historical Society. The Pennsylvania Historical and Museum Commission has placed three cast aluminum markers—Clinton County, Fort Reed, and Pennsylvania Canal (West Branch Division)—in Lock Haven to commemorate historic places. The Water Street District, a mix of 19th- and 20th-century architecture near the river, was added to the National Register of Historic Places in 1973. Memorial Park Site 36Cn164, an archaeological site of prehistoric significance discovered near the airport, was added to the National Register in 1982.