1 Best Sight in Billings, Little Big Horn, and the Montana Plains, Montana

Dutch architect Henry Hardenbergh, who worked on the original Waldorf-Astoria and Plaza hotels in New York City, designed this house in 1903 for businessman P.B. Moss. The mansion still contains many of the elaborate original furnishings, ranging in style from Moorish to art nouveau, which visitors can see on a self-guided tour. Don't miss the gem of a gift shop in the mansion's basement.