Tucked away in these spooky woodlands, one man has amassed a huge collection of decaying trolley cars. Once a novel mode of public transport in the likes early 20th Century New York, the hauntingly beautiful trolleys are now at one with nature – a scene that abandoned location photographer Matthew Christopher was able to discover in a location not disclosed to the public. Here: Abandoned trolley graveyard in Pennsylvania. (Photo by Matthew Christopher/Abandoned America/Caters News Agency)

These images of abandoned hospitals across Italy are not for the faint-hearted. Both of the hospitals featured in the photographs are Italian asylums – known as manicomios – that were used as mental hospitals. Shut down by law in 1978, the derelict buildings are visibly overgrown and make for very eerie portraits. Photographer Thomas Windisch, 32, of Graz, Austria, said the asylums, located in top-secret spots, can get very creepy when there aren't many people there with him. Here: a hallway within an abandoned hospital. (Photo by Thomas Windisch/Caters News)

“The World Stands on its Head” (“Die Welt Steht Kopf”) House on the Baltic Sea Island of Usedom stands nearly completed on September 3, 2008 in Trassenheide, Germany. The upside down house, complete with upside down interior furnishings, is the brainchild of Klaudiusz Golos and Sebastian Mikiciuk, and will become a local tourist attraction. (Photo by Sean Gallup/Getty Images)

This project features a house covered (inside and out) with thousands of round mirrors that makes it nearly camouflaged. The round mirrors have different shapes and size because each one was handcut by the artist. Visitors are in for a unique experience when the mirrors interactive with nature, glistening as it reflects sunlight while gently flickers when the wind blows.

One morning, this Redditor woke up to his front porch completely riddled with holes. It looked like some gang members spewed buckshot at his doorstep during a drive-by. These holes were made by acorn woodpeckers. The little birds created their own granaries or “acorn trees” to store their food. They do so by drilling holes into whatever they can, sometimes resulting in this kind of damage.

Bonbibi, Treehouse Point, Fall City, WA. The Bonbibi is balanced on two steel yokes. The yokes spread out the load and allow for tree growth and movement in the wind. A small deck hangs from the beams below and uses the treehouse itself to shelter guests. (Photo by Pete Nelson)