MILL VALLEY (CBS SF) — Another entry in the Bay Area’s bizarre housing market: an 1,100 square foot “tree house” is for sale in Mill Valley.

While not an actual tree house, the small cottage sits deep in a redwood grove with its own stream running alongside. The home is on just under one-third of an acre and is accessible only by a 130-step mountain trail.

The tree house was built in 1913, but has been completely upgraded with modern fixtures and radiant heat from the floor.

There are two bedrooms and one bathroom. The asking price is $679,000. For more information on the home, visit the Coldwell Banker website.