Star trails form over the Memorial House of the Bulgarian Communist Party on mount Buzludzha in this long exposure picture taken on September 12, 2014. The monument was officially opened in 1981 by the Bulgarian Communist regime to mark 100 years of the set up of an organised Socialist movement, a predecessor of the Bulgarian Communist Party. The monument, no longer maintained by the Bulgarian government after the fall of the Communist regime in 1989, is now abandoned and vandalized. (Photo by Stoyan Nenov/Reuters)

An Israeli soldier of the Caracal battalion smiles during a 23-kilometer march marking the end of their training in Israel's Negev desert, near Kibbutz Sde Boker February 14, 2013. The “Caracal” battalion, two-thirds of whose members are women, was established in 2004 with the purpose of incorporating female soldiers in combat units. The main mission of Caracal is routine patrols on Israel's border with Egypt to intercept infiltrators and smuggling from the Sinai desert. (Photo by Darren Whiteside/Reuters)

A Shi'ite Muslim man bleeds after tapping his forehead with a razor during a Muharram procession to mark Ashoura in Nabatieh town, southern Lebanon November 4, 2014. Ashoura, which falls on the 10th day of the Islamic month of Muharram, commemorates the death of Imam Hussein, grandson of Prophet Mohammad, who was killed in the seventh century battle of Kerbala. (Photo by Ali Hashisho/Reuters)

Tourists pose with pigeons in the flooded St. Mark's Square in Venice, on November 7, 2014. The high water, a combination of high tides and a strong Scirocco wind in the Adriatic Sea, stood at 110 centimeters early on November 7. The city has for years been wrestling with the problems posed by the threat of rising sea levels. (Photo by Olivier Morin/AFP Photo)

Dutch artist Daan Roosegaarde paid homage to Vincent Van Gogh's famous “Starry Night” painting by creating a glowing bike path relying on solar-powered LED lights. The 650-yard route which opened November 12, 2014 extends between Eindhoven and Neunen, Netherlands, where Van Gogh spent part of his life. Its the first event marking the 125th anniversary of Van Gogh's death July 29, 2015. (Photo by Pim Hendriksen/Studio Roosegaarde)

A tour group wanders through block 7 of Eastern State Penitentiary in Philadelphia, Pennsylvania April 30, 2014. Opened in 1829, with the original corrective system of “confinement in solitude with labor”, the penitentiary housed about 75,000 inmates in its 142 years of operation. At Eastern State reunions, former inmates, staff and guard gather to share memories and trade stories and get a chance to describe their experiences in question-and-answer sessions with the public. (Photo by Mark Makela/Reuters)

Sarah Gibbons grades a new batch of Maple Syrup at Gibbons Family Farm in Frankville, Ontario, Canada, 31 March 2014. The annual maple syrup season marks the end of the often brutal central Canadian winters and heralds the beginning of spring. The maple tree, whose leaf dominates the Canada's flag, plays both a symbolic and practical role in the identity of Canadians who produce around 95 percent of the world's supply of maple syrup. (Photo by Stephen Morrison/EPA)

High-wire artist Kane Petersen successfully walks a tightrope 300 metres above the ground at Eureka Skydeck on September 16, 2015 in Melbourne, Australia. The walk was the highest tightrope walk ever attempted in the Southern Hemisphere. The stunt is to mark the arrival of the film “The Walk” to Australian cinemas in October. The stunt saw Kane mimic the film's French high-wire artist Philippe Petit, who successfully walked between the twin towers of the World Trade Center in 1974. (Photo by Scott Barbour/Getty Images)