A colony of penguins gather with the Bark Europa in the background, on March 05, 2015 in South Georgia Island. An adventurer has documented his 5,000 miles journey aboard a 100-year-old ship, sailing from Argentina to Antarctica to Cape Town. (Photo by Andrew Orr/Barcroft Images)

“Rivers Forgotten” is a journey through the passages and portals of the underground waterways that lie unseen below cities. Self-taught photographer Jeremy Kai brings these forgotten landscapes to light. Photo: Beneath the Toronto area, 2011. (Photo by Jeremy Kai)

Last weekend, the National Building Museum in Washington, D.C., opened a 10,000 square-foot ball pit to the general public, and everyone cheered that, finally, someone made their childhood dreams come true.

“Tiger and Turtle–Magic Mountain” by German art duo Heike Mutter and Ulrich Genth is a walkable sculpture shaped like a roller coaster. Visitors can stroll along the track (except for the loop sections). The 69 foot tall sculpture is located in Wanheim Duisburg, Germany.

“The Glasswinged butterfly (Greta oto) is a brush-footed butterfly, and is a member of the subfamily Danainae, tribe Ithomiini, subtribe Godyridina”. – Wikipedia.

Brian Skerry can be called many things – explorer, journalist, conservation advocate – but he is first and foremost a photographer. His journeys to capture amazing underwater photographs have taken him across the world’s oceans. Photo: This Bahamian oceanic whitetip shark, known for the distinctive coloring on its white-tipped, rounded extremities, is part of a globally threatened species due to overfishing demands, primarily for its fins. (Photo by Brian Skerry)