Street musicians with their faces covered with animal masks play to earn some money in central Vienna, Austria, November 8, 2015. (Photo by Vasily Fedosenko/Reuters)

“Light From Heaven”. Taken around Mount Bromo, East Java, Indonesia in the morning. Photo location: East Java, Indonesia. (Photo and caption by Pimpin Nagawan/National Geographic Photo Contest)

ATTENTION! All pictures are presented in high resolution. To see Hi-Res images – just TWICE click on any picture. In other words, click small picture – opens the BIG picture. Click BIG picture – opens VERY BIG picture.

“Attacking Howler Monkey”. Due to a major tropical rainstorm my wife and I were forced to stay overnight in a Howler Monkey Rescue center in Panama. I used the time to explore the area and to take photos of the monkeys. Just after the rain finally stopped, I ran into this monkey that tried to mock attack me. I quickly took a couple of photos before retreating to a (more) safe distance. (Photo and caption by Christian Mueller-Planitz/National Geographic Traveler Photo Contest)

ATTENTION! All pictures are presented in high resolution. To see Hi-Res images – just TWICE click on any picture. In other words, click small picture – opens the BIG picture. Click BIG picture – opens VERY BIG picture.

Two robotic legged squad support system (LS3) machines by the Defense Advanced Research Project Agency follow a technician during a demonstration at Joint Base Myer-Henderson Hall, Virginia, on September 10, 2012. (U.S. Marine Corps photo by Sgt. Mallory S. VanderSchans via The Atlantic)

Villagers look on as Mount Sinabung volcano spews thick volcanic ash, as seen from Beganding village in Karo, North Sumatra province, on May 19, 2017. Sinabung roared back to life in 2010 for the first time in 400 years. After another period of inactivity, it erupted once more in 2013 and has remained highly active since. (Photo by Ivan Damanik/AFP Photo)

A doll, placed by stranded Iranian migrant protesters, hangs from barbed wire in front of Madedonian police at the Greek-Macedonian border near to the Greek village of Idomeni November 29, 2015. The protesters were demonstrating against what they say is the closure of the border for Iranian migrants. According to the demonstrators, the hanging toys and dolls represent the outcome of being unable to return, if they are sent back to Iran. (Photo by Yannis Behrakis/Reuters)

A woman takes a selfie in front of a Lunar New Year display featuring sheep at a shopping mall in Hong Kong, February 13, 2015. (Photo by Bobby Yip/Reuters)