The Rocks Estate, also known as the John Jacob Glessner Estate, is a historic summer estate in Bethlehem, New Hampshire. The large estate, covering more than 1,300 acres (530 ha), is located near the junction of U.S. Route 302 and Interstate 93, and includes some twenty buildings. The estate was assembled by John Jacob Glessner (whose Chicago residence is a National Historic Landmark designed by H. H. Richardson) in the 1880s, and is one of the largest and best-preserved surviving private estates in the state. Glessner created The Rocks as a private conservation initiative, to prevent destructive farming methods from destroying the land.