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)

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)

Father Christmas hands out presents to children at the Aid And Adoption Society home at Leytonstone. (Photo by Gerry Cranham/Fox Photos/Getty Images). 7th December 1938

French climber Alain Robert, also known as “Spiderman”, holds the flag of Nepal as he scales the Tour Montparnasse, a 210-metre (689 ft) building in central Paris, France April 28, 2015, to show support for the victims after the earthquake in Nepal. (Photo by Gonzalo Fuentes/Reuters)

Migrants scramble aboard a train at the station in Beli Manastir, Croatia September 18, 2015. Migrant numbers in Europe will build up in coming days and their flows may fragment further into new routes, the U.N. refugee agency said on Friday, urging the European Union to grasp a last chance to resolve the refugee crisis next week. (Photo by Laszlo Balogh/Reuters)