“Not for the faint of heart”. Casa Milà, better known as La Pedrera, is a building designed by the Catalan architect Antoni Gaudí and built during the years 1905–1910, being considered officially completed in 1912. It is located at 92, Passeig de Gràcia in the Eixample district of Barcelona, Catalonia, Spain. (Photo by Stefano Scarselli)

A round circle of smoke coming from the mouth of the Etna volcano is seen in the sky during an eruption on the southern Italian island of Sicily April 11, 2013. Mount Etna is Europe's tallest and most active volcano. (Photo by Antonio Parrinello/Reuters)

“The Mikoyan MiG-31 (NATO reporting name: Foxhound) is a supersonic interceptor aircraft developed to replace the MiG-25 “Foxbat”. The MiG-31 was designed by the Mikoyan design bureau based on the MiG-25”. – Wikipedia

Photos: The Mikoyan MiG-31 “Foxhound”. Russia, April 2012. (Photo by Alexandr Pak; Source: LiveJournal)

Faces adorn crosses placed in the Garden of Remembrance of some of Britain's armed forces members who have died in Afghanistan in the Garden of Remembrance outside Westminster Abbey at the official opening of the Royal British Legion's Field of Remembrance on November 5, 2009 in London, England. (Photo by Alastair Grant-Pool/Getty Images)

An Islamic religious leader and rebel supporter (R) chant to rally rebel fighters awaiting a rumored Libyan Army advance April 11, 2011 between the crucial towns of Ajdabiyah and Brega, Libya. Rebels continued to hold the strategic town of Ajdabiyah a day after NATO air power struck army troops loyal to Libyan ruler Moammar Gaddafi nearby, helping the rebels secure the city. (Photo by Chris Hondros/Getty Images)

A model walks the runway at the Dolores Cortes swim show during Mercedes-Benz Fashion Week Swim 2012 at The Raleigh on July 16, 2011 in Miami Beach, Florida. (Photo by Frazer Harrison/Getty Images for Dolores Cortes)