This three-story fortress with its 65-foot-high square tower was built by Golden contractor James H. Gow with 3,300 wagonloads of river rock from nearby Clear Creek. Locals boast it is the largest cobblestone structure in the world. Built by the National Guard Corps of Engineers, it initially had dormitories, a mess hall, drill hall, weapons storage rooms, a hospital, and an auditorium, but has been converted to shops and offices.