Ten natural arches: Utah sandstone spans, coastal openings in England and Chile, a river arch in France, and rock formations in Chad and China. Delicate Arch: NPS/Neal Herbert; Public domain (NPS government photograph); https://www.nps.gov/aboutus/disclaimer.htm; https://www.nps.gov/arch/planyourvisit/delicate-arch.htm; resized and fitted to portrait frame; derived image retains the stated source license. Landscape Arch: NPS/Veronica Verdin; Public domain (NPS government photograph); https://www.nps.gov/aboutus/disclaimer.htm; https://www.nps.gov/places/landscape-arch-trail.htm; resized and fitted to portrait frame; derived image retains the stated source license. Double Arch: Luca Galuzzi ( Lucag ); CC BY-SA 2.5; https://creativecommons.org/licenses/by-sa/2.5/; https://commons.wikimedia.org/wiki/File:USA_10439_Arches_National_Park_Luca_Galuzzi_2007.jpg; resized and fitted to portrait frame; derived image retains the stated source license. Rainbow Bridge: W. Bulach; CC BY-SA 4.0; https://creativecommons.org/licenses/by-sa/4.0/; https://commons.wikimedia.org/wiki/File:00_586_Rainbow_Bridge_%28Regenbogenbr%C3%BCcke%29_National_Monument%2C_Utah%2C_USA.jpg; resized and fitted to portrait frame; derived image retains the stated source license. Durdle Door: Saffron Blaze; CC BY-SA 3.0; https://creativecommons.org/licenses/by-sa/3.0/; https://commons.wikimedia.org/wiki/File:Durdle_Door_Overview.jpg; resized and fitted to portrait frame; derived image retains the stated source license. Pont d'Arc: Daniel VILLAFRUELA .; CC BY-SA 4.0; https://creativecommons.org/licenses/by-sa/4.0/; https://commons.wikimedia.org/wiki/File:Le_Pont_d%27Arc.jpg; resized and fitted to portrait frame; derived image retains the stated source license. Aloba Arch: AmIdRe; CC BY-SA 4.0; https://creativecommons.org/licenses/by-sa/4.0/; https://commons.wikimedia.org/wiki/File:Aloba_T15b_5831b.JPG; resized and fitted to portrait frame; derived image retains the stated source license. Shipton's Arch: Philipp Reichmuth; CC BY-SA 4.0; https://creativecommons.org/licenses/by-sa/4.0/; https://commons.wikimedia.org/wiki/File:ShiptonsArchHDR.jpg; resized and fitted to portrait frame; derived image retains the stated source license. Moon Hill: Maria Ly; CC BY 2.0; https://creativecommons.org/licenses/by/2.0/; https://commons.wikimedia.org/wiki/File:Moon_Hill_-_Yangshuo%2C_China.jpg; resized and fitted to portrait frame; derived image retains the stated source license. La Portada: Adolto Toloza; CC BY-SA 3.0; https://creativecommons.org/licenses/by-sa/3.0/; https://commons.wikimedia.org/wiki/File:La_Portada%2C_Antofagasta_-_panoramio.jpg; resized and fitted to portrait frame; derived image retains the stated source license.