The Cranes' Treehouse, as seen in the intro, with Munchy Beaver sitting across from it.
The Cranes' Treehouse is where Cap'n Crane and his wife Connie Crane reside. Unlike most of the homes, which are usually docked in the lake, the treehouse is set onto an actual tree, with a ladder that leads up from the ground. There is a 'crow's nest', the kind seen on a ship, on top of the tree, where Cap'n and Connie are usually on lookout.
In the story Watchbird Alert, the treehouse gets knocked down, so the Otters invite the Cranes to stay over at their houseboat until their home can be replaced.