A replica of pre-historic drawings showing horses, rhinoceros and aurochs is seen on a wall during a press visit at the site of the Cavern of Pont-d'Arc project in Vallon Pont d'Arc April 8, 2015. The Cavern of Pont-d'Arc project is a replica of the pre-historic Decorated Cave of Pont-d'Arc known as Grotte Chauvet, in Vallon Pont-d'Arc in the Ardeche region, containing the world's earliest known art which was recently named a UNESCO World Heritage site. The facsimile cavern, which condenses some 8000m² of the original site into 3000m², will display faithful reproductions of paintings and engravings and will be inaugurated on April 10 and will open to the public on April 25. (Photo by Robert Pratta/Reuters)

A woman (L) places flowers at a grave next to a mummified body during exhumation works at the General Cemetery in Guatemala City, April 15, 2015. If a lease on a grave has expired or not been paid, grave cleaners will break open the crypts to remove and rebury the bodies. Any remains that have not been claimed are packed into plastic bags, labeled and stored in mass graves. Bodies that have been stored in the upper crypt are exposed to dry and sunny conditions which means they do not decompose and instead become mummified. (Photo by Jorge Dan Lopez/Reuters)

A woman strikes a police truck with her hand during a protest march in Santiago, Chile, Thursday, April 16, 2015. Thousands of students marched through the streets of Chile's capital to protest recent corruption scandals and to complain about delays in a promised education overhaul. While it was largely peaceful, violence broke out at the end when hooded protesters threw rocks and gasoline bombs at police. (Photo by Luis Hidalgo/AP Photo)

A devotee holds incense sticks while celebrating the Sindoor Jatra Festival on April 15, 2015 in Thimi, Nepal. Sindoor Jatra Festival is celebrated each year in Thimi, on the outskirts of Kathmandu, to welcome the Nepali New Year and celebrate the coming of spring. During the Festival, devotees are smeared with vermillion powder and 30 chariots containing the images of several gods and goddesses are carrying by the devotees around the town, while others sing, dance and play musical instruments. (Photo by Omar Havana/Getty Images)

Participants wearing superhero costumes attend the World DC Comics Super Heroes event in San Martin de Valdeiglesias, near Madrid, April 18, 2015. To celebrate the anniversary of the publication of the very first Superman story, DC Comics are asking fans to help set a new world record for the largest global gathering of people dressed as DC Comics Super Heroes. (Photo by Andrea Comas/Reuters)

General view of Chilean Calbuco volcano from Puerto Montt, located at 1000 km southern Santiago de Chile, Chile, 22 April 2015. Due to the eruption of the volcano with a smoke column 20 km high, authorities declared a red alert and ordered the evacuation of around 1500 inhabitants of Ensenada, Alerce, Colonia Río Sur and Correntoso towns. (Photo by Alex Vidal Brecas/EPA)

Fishermen jump into a small river to catch trout as they celebrate Fischertag (Fisherman's Day) in downtown Memmingen, southern Germany, July 25, 2015. The annual Fisherman's Day (Fischertag) tradition goes back to the year of 1465 where every fisherman who were born in Memmingen tries to catch trout from the river. The participant who catches the biggest trout will be named the “Fisher King” for one year. (Photo by Michaela Rehle/Reuters)

The moon rises over people gathered on Glastonbury Tor ahead of tomorrow's Blue Moon on July 30, 2015 in Somerset, England. The full moon appearing on July 31 will be what's called a Blue Moon, which refers to the second of two full moons appearing in the same calendar month. The last time this happened was in 2012 and there isn't due another until 2018. (Photo by Matt Cardy/Getty Images)