The Famous One Log House is a one-bedroom house hollowed out from a single log that came from a 2,100-year old redwood tree:
After felling this 13 foot diameter forest giant, Art Schmock and a helper needed 8 months of hard labor to hollow out the log into a room 7 ft. high and 32 ft. long, weighing about 42 tons.
Link - via Crazytopics