Vietnam’s Son Doong cave, the largest in the world, could hold a 40-story skyscraper inside. The pristine ecosystem has its own river and jungle. Despite its size, Son Doong wasn’t discovered until 1991. It was lost again for nearly two decades and was fully explored for the first time in 2009. (Photo by Jason Speth/HuffPost)

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)

A young girl navigates her way around Hampton Court maze in the spring sunshine on May 2, 2009 in London, England. The Hampton Court maze is one of the most famous hedge mazes in the world and was planted between 1689 and 1695 by George London and Henry Wise. (Photo by Dan Kitwood/Getty Images)

Meerkats at ZSL (Zoological Society of London) London Zoo received an early Christmas gift from their keepers of home-made crackers filled with meal worms and locusts on December 17, 2009 in London, England. (Photo by Oli Scarff/Getty Images)

“Ecotricity's Greenbird vehicle, designed and piloted by Richard Jenkins, broke the land speed world record for a wind-powered vehicle in 2009. Greenbird recorded a top speed of 126.4 mph (203.4 km/h), and sustained a speed of 126.2 mph (203.1 km/h) for the required time of three seconds, beating the previous, American held, record of 116 mph (186.7 km/h), set by Bob Schumacher in the Iron Duck in March 1999 at the same location”. – Wikipedia

Photo: Richard Jenkins poses for photographs with the world's fastest wind powered land Vehicle at Science Museum on August 3, 2009 in London, England. (Photo by Dan Kitwood/Getty Images)

For the Torajan people of Indonesia, death is part of a spiritual journey: families keep the mummified remains of their deceased relatives in their homes for years – and traditionally invite them to join for lunch on a daily basis – before they are eventually buried. Here: Todeng died in 2009. A young relative of his, Sam, lights him a cigarette and changes his glasses. (Photo by Claudio Sieber Photography/The Guardian)

Actress Lindsay Lohan and DJ Samantha Ronson attend the Charlotte Ronson Spring 2009 fashion show during Mercedes-Benz Fashion Week at The Promenade in Bryant Park on September 6, 2008 in New York City. (Photo by Stephen Lovekin/Getty Images for IMG)