Elmridge (also known as Elm Ridge, or James Gardiner Coffin House, or J.G. Coffin House or John Walker House) located at 1 Breck Drive in Leetsdale, Pennsylvania, was built in 1869. The architectural plans were published in Hobbs Architecture, 1873. The house was added to the National Register of Historic Places on May 10, 2005, and to the List of Pittsburgh History and Landmarks Foundation Historic Landmarks in 2007. It is also incredibly haunted, as is the rest of the hill it is located on.