Gdańsk is a Polish city on the Baltic coast. The city's professional football club is Lechia Gdansk. Founded in 1945, they play in the Ekstraklasa, Poland's top division. The European Football Championship will take place in Gdansk 2012.

Photo by: Sludgegulper ; Source: Flickr

A man takes a picture of part of what is set to be the UK's largest street art project on August 19, 2011 in Bristol, England. The See No Evil art project on Nelson Street in Bristol will see several multi story buildings in the street covered with art over the coming days. Organisers hope that the project, which has involved top graffiti artists from all over the world, will become a major tourist attraction for the west country city, often said to the spiritual home of Banksy. (Photo by Matt Cardy/Getty Images)

Bouboule, an English bulldog rests in its hotel room at Actuel Dogs on April 19, 2011 in Vincennes, France. Opened in November 2010 by Devi and Stan Burun, Actuel Dogs is a five-star luxury hotel for dogs with four single rooms and two suites. With the aim of meeting the dogs' needs, the hotel offers activities including doggy walks, doggy rando (hiking), doggy jogs, doggy velo (running next to a bike) and other services such as dog massage. The hotel also caters to the needs of people living in small appartments or who don't have the time to walk their dogs. (Photo by Franck Prevel/Getty Images)

CANNES, FRANCE - NOVEMBER 03: Italian Prime Minister Silvio Berlusconi leaves the conference centre after the first day of the G20 Summit on November 3, 2011 in Cannes, France. World's top economic leaders are attending the G20 summit in Cannes on November 3rd and 4th, and are expected to debate current issues surrounding the global financial system in the hope of fending off a global recession and finding an answer to the Eurozone crisis. (Photo by Dan Kitwood/Getty Images)

“Photoswapped: Mum and dads switch heads with their children in freakiest photos you'll ever see. It is a position that many young children would love to be in. And now these strange and sometimes unnerving images show what it would actually be like if babies swapped roles, and heads, with their mother or father. The photos, created by top advertising photographer Paul Ripke, are so eye-catching that they have swept across the world online”. (Photo by Paul Ripke/Barcroft Media via Fame Pictures)

These photographs are the work of urban explorer Dr Bradley Garrett who made headlines back in 2012 when he posted a series of snaps from the top of The Shard skyscraper while it was still under construction. Garrett, now a researcher at the University of Oxford, took these shots during his time with the London Consolidation Crew (LCC), a loose collection of urban explorers based in the English capital. Photo: Bradley Garrett stands on the edge of the Ritz-Carlton Chicago as lightning strikes in the distance in Chicago, US. (Photo by Bradley L. Garrett/Barcroft Media)

A cenote is a natural phenomenon, a sinkhole in the Earth’s surface. The Yucatan Peninsula in Mexico has an estimated 7,000 cenotes because it is primarily made up of porous limestone. For millions of years, rainfall slowly ate away at the limestone and a huge system of underground caves and caverns was formed. Many filled with water from rain or from the underground water table. When the roof of a water filled cave collapses, a cenote is born. The water found in a cenote may be fresh water, salt water, or both. Structurally it may be completely open, like a lake, almost completely closed with just a small opening at the top, or somewhere in between.