19. Maltese cross-cabins
This historic US house is easily the smallest on the list, but it's incredibly rich in history. The Maltese Cross Cabin, just outside Medora, North Dakota, was once the home of US President Theodore Roosevelt in the Northern Badlands.
Roosevelt then said of his time in North Dakota, "I wouldn't be President without my experience in North Dakota." One of his most important commitments as president was establishing the preservation of public lands, a goal strongly inspired by his time in the cabin and the Dakota Territory at large.
