A visitor tries out the new glass Skywalk at the top of the refurbished Blackpool Tower on September 1, 2011 in Blackpool, England. After a GBP Ј20 million refurbishment, the iconic seaside Blackpool Tower opened today to the general public. The observation deck at the top of the tower becomes the Blackpool Tower Eye and features a skywalk made of glass overlooking the sea and the promenade. The opening is part of Blackpool's GBP Ј250 million GBP regeneration project. (Photo by Christopher Furlong/Getty Images)

Men rest after salvaging metal on the 30th floor of the “Tower of David” skyscraper in Caracas February 3, 2014. A 45-storey skyscraper in the center of Venezuela's capital Caracas is a slum, probably the highest in the world. Dubbed the “Tower of David”, the building was intended to be a shining new financial center but was abandoned around 1994 after the death of its developer – banker and horse-breeder David Brillembourg – and the collapse of the financial sector. (Photo by Jorge Silva/Reuters)

Guest gather in the street as the wait to attend the annual New York City Diner en Blanc, August 22, 2017 held this year at the plaza at Lincoln Center. The Diner en Blanc, the worlds only viral culinary event, a chic secret pop-up style picnic from France, the outdoor site – always a landmark location – is revealed at the last-minute. Guests are asked to dress entirely in elegant white, bring a picnic basket of food, fine china and silverware, white tablecloths, table and chairs. (Photo by Timothy A. Clary/AFP Photo)

NYC morning fog. Wednsday, January 15, 2014, morning dense fog creates spectacular views over the East river of lower Manhattan, Brooklyn and Manhattan bridges as New Yorkers and tourist admire the scenery. View from Brooklyn Bridge Park in DUMBO Brooklyn. (Photo by Paul Martinka/New York Post)

Photographer Martin Schoeller examines the visual nuances of twins. Schoeller was born in Munich, Germany in 1968, studied photography at Lette Verein in Berlin and lives in New York. (Photo by Martin Schoeller)

India: A sweeper cleans the side of a road near a replica of the Eiffel Tower amid heavy fog in the early morning in the northern Indian city of Chandigarh January 18, 2010. (Photo by Ajay Verma/Reuters)

Zookeeper Michael Horn holds up Kit and Kitty, the twin red pandas born in June on the first day of their introduction into their new enclosure at Tierpark Zoo on September 13, 2011 in Berlin, Germany. The red panda (Ailerus fulgens) is a rare mammal native to the eastern Himalayas and southwestern China. (Photo by Sean Gallup/Getty Images)

Conjoined twins Angelica (C) and Angelina Sabuco (L) play with child life specialist Allison Brooks during a press conference at the Lucile Packard Children's Hospital at Stanford on October 31, 2011 in Palo Alto, California. Two year-old conjoined twins Angelica and Angelina Subaco who are connected at the chest and abdomen are preparing for separation surgery by Dr. Gary Hartman. The surgery will last between 6 and 8 hours that is followed by three hours of reconstructive surgery for each girl. (Photo by Justin Sullivan/Getty Images)