The Copper King Mansion, also known as the W. A. Clark Mansion, is a 34-room residence of Romanesque Revival Victorian architecture that was built from 1884 to 1888 as the Butte, Montana, residence of William Andrews Clark, one of Montana's three famous Copper Kings. The home features fresco painted ceilings, elegant parquets of rare imported wood, gas and electric chandeliers, ornate hand-carved fireplaces and stairways, and stained-glass windows. The mansion was added to the National Register of Historic Places in 1970.