Vietnam’s Son Doong cave, the largest in the world, could hold a 40-story skyscraper inside. The pristine ecosystem has its own river and jungle. Despite its size, Son Doong wasn’t discovered until 1991. It was lost again for nearly two decades and was fully explored for the first time in 2009. (Photo by Jason Speth/HuffPost)
“A Mothers Tail”. A baby cub pulls on his mother's tail to get attention. Photo location: Masai Mara, Kenya. (Photo and caption by Tori Marsh/National Geographic Photo Contest)
Actor and former California Governor Arnold Schwarzenegger (R) and his son Patrick Schwarzenegger (L) attend “Arnold Classic Europe” 2011 Party at “Jardines Cecilio Rodriguez” on October 7, 2011 in Madrid, Spain. (Photo by Carlos Alvarez/Getty Images)
Palestinian woman Jihan Abu Muhsen prepares her donkey with her son Kareem before going work collecting bricks for sale from sites of demolished buildings, at her dwelling in Khan Younis in the southern Gaza Strip March 8, 2016. Abu Muhsen gathers bricks from the sites of demolished buildings and sells them to recycling factories. She earns around 20 shekels ($5) a day and her 10-year-old son Mohammad helps her when he is not at school. (Photo by Ibraheem Abu Mustafa/Reuters)
Japanese embroidery artist Hiroko Kubota was in the process of making custom sized clothes for her smaller-framed son when he made a small request: could some of the shirts have cats on them? Kubota explains her son was somewhat obsessed with cats and had collected a small library of adorable images found around the web.
A man washes his horse as a woman bathes her son at concrete water pens under a flyover in a slum area in Kolkata, India October 21, 2016. (Photo by Rupak De Chowdhuri/Reuters)