On the western side of Mount Hood lies the longest glacier cave system in the contiguous United States. In 2012, these caves were mapped to a combined length of 7,166.8 feet by cave explorers Brent McGregor and Eddy Cartaya. Currently, the total passage length is hundreds of feet less. Glaciers are frozen rivers; they are always moving and changing... (Photo and caption by Josh Hydeman)

A destroyed tank sits by the side of a road leading to Abi Adi, in the Tigray region of northern Ethiopia, on Tuesday, May 11, 2021. The Tigray People’s Liberation Front was on top of a coalition that ruled Ethiopia for nearly three decades. That changed in 2018, when Prime Minister Abiy Ahmed rose to power as a reformist. Abiy alienated the TPLF with efforts to make peace with its archenemy, Eritrea, and rid the federal government of corruption. (Photo by Ben Curtis/AP Photo)

St. Mark's and Panagia Erithiani church congregations perform “Rocket War” by firing thousands of home-made rockets across the sky during Greek Orthodox Easter celebrations in the town of Vrontados on the Greek island of Chios on April 19, 2014. Greek habit of throwing handmade rockets with the aim of hitting the bell tower of the church at the other side during the celebration of the service at midnight before Easter Sunday. (Photo by Cem Oksuz/Anadolu Agency/Getty Images)

Cocoa Beach, Florida, USA. 7th October, 2016. Kaleigh Black, 14, left, and Amber Olsen, 12, run for cover as a squall with rain and wind pelt them while they explore the Cocoa Beach Pier on Friday (10/7/16) after hurricane Matthew passed to the east on Florida's east coast.(Photo by Douglas R. Clifford/Tampa Bay Times/ZUMA Wire/Alamy Live News)

Fans of the East German Trabant car gather for their 7th annual get-together on August 23, 2014 in Zwickau, Germany. Hundreds of Trabant enthusiasts arrived to spend the weekend admiring each others cars, trading stories and enjoying activities. The Trabant, dinky and small by modern standards, was the iconic car produced in former communist East Germany and today has a strong cult following. (Photo by Matthias Rietschel/Getty Images)

West Berliners crowd in front of the Berlin Wall as they watch East German border guards demolish a section of the wall on November 11, 1989. (Photo by Gerard Malie/AFP Photo)

A tamed hawk attacks a rabbit during the traditional hunting contest outside the village of Nura, east from Almaty, Kazakhstan, February 13, 2016. (Photo by Shamil Zhumatov/Reuters)