Spanning 350 acres across Flathead Lake, Cromwell Island is a private oasis in the Montana wilderness. Cromwell Island was purchased in the late 1980s by Robert M. Lee, a renowned automobile and antique arms collector, explorer, author, and conservationist. Before his death in 2016, Mr. Lee and his wife, Anne, partially completed the construction of the monumental structure including over 45,000 square feet of living space that was to serve as their home full-time. Even in its unfinished state, it has a magnitude of presence reminiscent of Versailles. The property offers 3 miles of shoreline in the largest freshwater lake west of the Mississippi River and affords direct views of the Mission Mountains. It comes with a 45,000-square-foot residence with a terra-cotta roof, mahogany windows, and a concrete facade made to look like Montana Travertine. Its interior has been left unfinished and can be completed to the new owner’s liking. The property also includes a two-bedroom guest house, an underground shooting range, and a boat dock with five slips. The catch? The price. £57.5 Million, Find out more Hallhall.com