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)

The Spirit of Ecstasy, also called “Emily”, “Silver Lady” or “Flying Lady,” was designed by English sculptor Charles Robinson Sykes and carries with her a story about a secret passion between John Walter Edward Douglas-Scott-Montagu (second Lord Montagu of Beaulieu after 1905, a pioneer of the automobile movement, and editor of The Car Illustrated magazine) and his love and the model for the emblem, his secretary Eleanor Velasco Thornton. Photo: Worker Ronald Little displays a finished “Spirit of Ecstasy”. (Photo by Stefan Wermuth/Reuters)

Russian honour guards march during the military parade at Red Square in Moscow on November 7, 2018. Russia marks the 77th anniversary of the 1941 historical parade, when Red Army soldiers marched past the Kremlin walls towards the front line to fight Nazi Germany troops during World War Two. (Photo by Mladen Antonov/AFP Photo)

People in historical uniforms prepare for a parade at Red Square commemorating the 75th anniversary of the Red Army’s defence of Moscow during the second world war in Moscow, Russia on November 7, 2016. (Photo by Stanislav Krasilnikov/TASS)

Crowds wave as HMS Daring, the largest and most powerful destroyer warship ever built for the Royal Navy, leaves Portsmouth Harbour on January 11, 2012 in Portsmouth, England. HMS Daring, the first of six new Type 45 destroyers embarked from Portsmouth on its maiden deployment, a seven-month mission to the Middle East. (Photo by Matt Cardy/Getty Images)

The new Amazon tablet called the Kindle Fire is displayed on September 28, 2011 in New York City. The Fire, which will be priced at $199, is an expanded version of the company's Kindle e-reader that has 8GB of storage and WiFi. The Fire gives users access to streaming video, as well as e-books, apps and music, and has a Web browser. In addition to the Fire, Bezos introduced four new Kindles including a Kindle touch model. (Photo by Spencer Platt/Getty Images)

Migrants with a stick, stones and knife fight with each other after a brawl erupted over a place in an overcrowded train heading to the Serbian border at the train station in Gevgelija, The Former Yugoslav Republic of Macedonia, 14 August 2015. The number of migrants passing through Macedonia increases day by day, local sources said. From the beginning of the year to mid-June 2015, nearly 160,000 migrants landed in the southern European countries, mainly Greece and Italy, on their way to wealthier countries in Western and Northern Europe, according to estimates by the International Organization for Migration (IOM). (Photo by Georgi Licovski/EPA)