W. W. Hartwell House & Dependencies

W. W. Hartwell House & Dependencies, also known as Regina Maria Retreat House, is a historic home located at Plattsburgh in Clinton County, New York. It was built about 1870 and is an elaborate stone mansion featuring a three-story tower with a Mansard roof in the Second Empire style. The house is set among park-like landscaping. Also on the property are a cottage and a stone carriage house.

It was listed on the National Register of Historic Places in 1982.