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)

Dharma the Sumatran tiger yawns as members of the public return to Edinburgh Zoo as it opens for the first time following the easing of Scottish Governments lockdown restrictions on June 29, 2020 in Edinburgh, Scotland. Outdoor visitor attractions in Scotland have reopened along with many non-essential retailers after more than three months in lockdown, as Scotland moves into phase 2 of its “route map” for easing coronavirus restrictions. (Photo by Jeff J. Mitchell/Getty Images)

Jenn Brown of CFX (Composite Effects) adjusts a silicon mask based on Pinhead from the movie franchise “Hellraiser” in their stall during Preview Night at the 2022 Comic-Con International at the San Diego Convention Center, Wednesday, July 20, 2022, in San Diego. (Photo by Chris Pizzello/AP Photo)

A man walks near a artwork of Italian artist Dario Agrimi entitled “ascesa” during a press preview of the first edition of “Roma Arte in Nuvola”, the international fair of modern and contemporary art in Rome on November 18, 2021 at the Roma Convention Center “La Nuvola”. (Photo by Tiziana Fabi/AFP Photo)

Members of the Unidos da Tijuca samba school parade at the “Opening of Carnival 2022” event, at the Cidade do Samba, in Rio de Janeiro, Brazil, 27 February 2022. The event is a preview of the parades of the Samba Schools of the Special Group, postponed to April due to the COVID-19 pandemic in Brazil. (Photo by Andre CoelhoEPA/EFE)

A woman looks at jellyfish during a media preview for the Epson Aqua Park Shinagawa aquarium's re-opening in Tokyo July 6, 2015. The aquarium will re-open on July 10 with new attractions including a pirate ship ride and a merry-go-round. (Photo by Toru Hanai/Reuters)

The “EMIEW3” robot (R) demonstrates communicating with a visitor during a press preview in Tokyo on April 8, 2016. Japanese electronics giant Hitachi unveiled its humanoid customer service and guidance robot “EMIEW3” and “remote brain” robotics IT platform. (Photo by Toshifumi Kitamura/AFP Photo)

Tourists take a panoramic view of Kuala Lumpur from a skybox during a media preview at Kuala Lumpur Tower in Kuala Lumpur, Malaysia, 05 May 2016. Skybox, 421 metres above ground level will be the latest tourists attraction at Kuala Lumpur Tower, the 7th tallest freestanding tower in the world. (Photo by Ahmad Yusni/EPA)