A tree house, tree fort or treeshed, is a platform or building constructed around, next to or among the trunk or branches of one or more mature trees while above ground level. Tree houses can be used for recreation, work space, habitation, a hangout space and observation. People occasionally connect ladders or staircases to get up to the platforms.
A tree house in the park of the Château de Langeais in the Loire Valley, France
Papuan tree house in British New Guinea, 1885
A stairway and roundwalk
Strutted treehouse utilizing tree attachment bolts in a public park in Burlington, Vermont
A nest is a structure built for certain animals to hold eggs or young. Although nests are most closely associated with birds, members of all classes of vertebrates and some invertebrates construct nests. They may be composed of organic material such as twigs, grass, and leaves, or may be a simple depression in the ground, or a hole in a rock, tree, or building. Human-made materials, such as string, plastic, cloth, or paper, may also be used. Nests can be found in all types of habitat.
The elaborate bird nest of a baya weaver
A night heron building a nest
Swans with nest and eggs at Lake Constance
A dusky woodswallow parent feeding chicks in a nest at Mortimer Bay, Tasmania, Australia.
