Thordarson Estate Boathouse (Rock Island)

The boathouse completed in 1929 is the first thing visitors see arriving at Rock Island — limestone walls, round-arched windows on both floors, and interior Icelandic runes carved into a structure designed by architect Frederick P. Dinkelberg. Chester Thordarson, an Icelandic-born inventor who held nearly a hundred patents related to transformers and helped shape the modern electrical grid, purchased the island in 1910 and built this as his private retreat's outpost. It's been part of the National Register's Thordarson Estate Historic District since 1985. The Friends of Rock Island still maintain it, and it's still open to visitors who make the two-ferry crossing.