Men watch model trains running along the bar at Bar Ginza Panorama Shibuya Branch on June 3, 2009 in Tokyo, Japan. The bar caters to model train enthusists and customers are able to bring their own model trains to run on the tracks. (Photo by Junko Kimura/Getty Images)

Pigs race around the track at the Pig Racing and Diving display at the Sydney Royal Easter Show on April 10, 2009 in Sydney, Australia. (Photo by Mark Kolbe/Getty Images)

Dargavs is a small necropolis outside the village of Dargavs in North Ossetia-Alania. It comprises 99 different tombs and crypts. It is often called city of the dead. Some sources say the oldest of the crypts dates back to the 12th century, though others say the oldest crypt dates back to 14th century and some say it dates to the 16th century. At the back of the complex there is a tower, though the top of it is destroyed.

Opossums on their mothers back at a game reserve in Central Minnesota, USA, on September 2, 2013. (Photo by Caters News Agency)

Greyhounds with stuffed and sprung model monkeys strapped to their backs before a hurdle race at Wellinborough. (Photo by E. Bacon). 21st April 1928

A mouse rides on the back of a frog in floodwaters in the northern Indian city Lucknow June 30, 2006. (Photo by Pawan Kumar/Reuters)