The Tree House

The Tree House is a private clubhouse where Arthur and his friends go to hide away from D.W., so that they can do homework, play games, spend time together, and many other things in peace. It is located in Northwest Elwood City and it is a few blocks from the Reads' house. It first appeared in the book Arthur's Valentine. In Castles in the Sky, it revealed a background story where Arthur and his friends established it since kindergarten, and during the cold winter in third grade, it collapsed and Arthur's friends were planning various ways to a new one, but Arthur only liked the original, so they restored it that way.

Description
The tree house has a wooden structure at the tree tops of a tall tree and many wooden steps to climb up and down. There is also a rope on the branch. The tree house was originally a short tree with a few steps, and was entered aside from climbing up. In the book Arthur's Birthday, the tree house was re-designed with a taller tree, more steps to climb, and it was entered directly from climbing up. After being redesigned, it originally had a four-sectioned window, but the cartoon and later books replaced the window with a six-sectioned one. The window has a bluish-green curtain on the inside. In the books, the words "KEEP OUT!" was written to prohibit anyone from entering the tree house, unless he or she was one of Arthur's friends.