The twin treehouses
Usually when you have a sister or a brother, you want always what he/she has. For this reason a lot of times parents take two objects of the same thing, so that they sons will not fight for it. I guess that something similar happen also with this treehouse!
In two different trees have been built the same treehouse. The houses are one the copy of the other and are connected with a bridge. Just the stairs are different, because of the trunk.