A young visitor interacts with a baby hippopotamus swimming in its enclosure at the Berlin Zoo on January 1, 2018. Tourists and locals flocked to the zoo in the German capital on the unseasonably warm first day of the year. (Photo by Odd Andersen/AFP Photo)

Teenage girls are all steamed up these days about straight hair. The steam iron is replacing the huge rollers on which countless teens slept every night to achieve the height and curls fashionable until. The same girls endure having their hair stretched to absolute straightness on the ironing board, and then ironed to keep it that way. Unlike the roller setting, this takes teamwork. Gay Stilley, 14, goes through an ironing session with a couple of her friends at the Stilley Home in Glen Oaks, Queens, New York City on December 23, 1964. With a wary eye, Gay tries to watch the straightening process as one friend stretches her hair with a comb and another does the ironing, in the Stilley kitchen. (Photo by Marty Zimmerman/AP Photo)

In this Wednesday, January 3, 2018 photo, yoga instructor Danuta Wolk-Laniewski, demonstrates goat yoga at the Aussakita Acres farm in Manchester, Conn. The farm is partnering with the Hartford Yard Goats, the Double-A affiliate of the Colorado Rockies baseball team, to offer goat yoga at Dunkin Donuts Park, the team's $71 million stadium in Hartford. (Photo by Pat Eaton-Robb/AP Photo)

His own space suit, with oxygen tank, doesn't make Barney the monkey any happier as he and actor Adam West view the situation in their space capsule in Hollywood on January 24, 1964. Barney, a South American woolly monkey, is blasted into space with West, as an astronaut, in a new movie, “Robinson Crusoe on Mars”. (Photo by AP Photo)

A Hindu devotee in a trance on their pilgrimage to the Batu Caves temple in Kuala Lumpur, Malaysia on January 28, 2018. Malaysian Hindu participate in the annual Hindu thanksgiving festival in which devotees subject themselves to painful rituals in a demonstration of faith and penance held in honour of Lord Murugan, Hindu in Malaysia celebrated Thaipusam begin on Jan 28 until 31 this year. (Photo by Aflo/Rex Features/Shutterstock)

“Left behind” children Luo Hongni, 11 (L) and brother Luo Gan,10, carry flowers to be used as feed while doing chores in the fields on December 18, 2016 in Anshun, China. Like millions of Chinese children, the four Luo siblings are being raised by their grandparents in rural China as their parents left to find work in urban areas. (Photo by Kevin Frayer/Getty Images)

A model, painted by the artist Avi Ram from Airbrush Hero, poses for a photo as part of a calendar project, at the Tower of David in Jerusalem's Old City, April 27, 2017. (Photo by Ronen Zvulun/Reuters)

Located in the Mokattam Mountain in southeastern Cairo, Egypt, the Monastery of Saint Simon or the Cave Church is a beautiful and mystical location. The area is also known under the name of the “garbage city” because of the large population of garbage collectors or Zabbaleen that live here and who are the descendants of farmers who started migrating from Upper Egypt to Cairo in the 1940s.