Photo Credits
All photos: Wikimedia Commons and Flickr.

creative commons

Deserts quiz
Arabian Desert: Jan Tito (cc by-sa)
Atacama Desert: Heretiq (public domain)
Black Rock Desert: Ian Kluft (cc by-sa)
Chihuahua Desert: Cryptocône (cc by-sa)
Gobi Desert: Aineias (cc by-sa)
Great Victoria Desert: Amanda Slater (cc by-sa)
Great Sandy Desert: Laurence Norah (cc by-nc-sa)
Kalahari Desert: Elmar Thiel (cc by)
Karakum Desert: NASA (public domain)
Mojave Desert: Mark A. Wilson (public domain)
Namib Desert: Luca Galuzzi (cc by-sa)
Negev: Matthew Parker (cc by-sa)
Patagonian Desert: Eassi (cc by)
Sahara: Michal Osmenda (cc by-sa)
Simpson: Paul Hanly (cc by)
Sinai: Mark A. Wilson (public domain)
Sonoran Desert: Santryl (cc by-sa)
Tabernas Desert: Emilio del Prado (cc by-sa)
Taklamakan Desert: Pravit (cc by-sa)
Thar Desert: Sushmita Balasubramani (cc by)

Islands quiz
Baffin Island: NASA (public domain)
Borneo: Tom (cc by-sa)
Cuba: Bitboy (cc by)
Great Britain: Addie Schulte (public domain)
Greenland: Jensbn (cc by-sa)
Hispaniola: Michelle Walz (cc by)
Honshu: Morio (cc by-sa)
Iceland: Roger McLassus (cc by-sa)
Java: Java Tourism (cc by)
Luzon: Eric Molina (cc by)
Madagascar: Moongateclimber (public domain)
Newfoundland: Natalie Lucier (cc by-nc-sa)
New Guinea: eGuide Travel (cc by)
Sakhalin: Brian Tibbets (public domain)
Sicily: Giovanni (cc by-nc-sa)
South Island: Michael Button (cc by)
Sri Lanka: Anuradha Ratnaweera (cc by-sa)
Sumatra: Mark Veraart (cc by)
Tasmania: Bjørn Christian Tørrissen (cc by-sa)
Tierra del Fuego: Claudio Elias (cc by-sa)

Lakes quiz
Aral Sea: NASA (public domain)
Caspian Sea: Dragon Oil (cc by-sa)
Dead Sea: David Shankbone (cc by-sa)
Great Bear Lake: Matcatpurple (cc by-sa)
Great Lakes: Pete Markham (cc by-sa)
Great Slave Lake: David Adamec (public domain)
Lake Baikal: Sansculotte (cc by-sa)
Lake Chad: NASA (public domain)
Lake Eyre: Matt Malone (public domain)
Lake Geneva: Schnäggli (cc by-sa)
Lake Ladoga: Kahkonen (public domain)
Lake Malawi: Stefan7 (cc by-sa)
Lake Maracaibo: Wilfredo R. Rodriguez H. (public domain)
Lake Nicaragua: Addie Schulte (public domain)
Lake Tanganyika: Wordtraveller (cc by-sa)
Lake Titicaca: Sylvio (public domain)
Lake Toba: Kodibuddi (public domain)
Lake Victoria: Damiano Luchetti (public domain)
Qinghai Lake: Yolki (cc by)
Tonlé Sap: Taguelmoust (cc by-sa)

Metropolitan areas
Beijing: CobbleCC (cc by-sa)
Cairo: Raduasandei (public domain)
Delhi: Sutirthobukka (cc by-sa)
Dhaka: Tanweer Morshed (public domain)
Istanbul: Hakan Sarıtaş (cc by)
Jakarta: Gunawan Kartapranata (cc by-sa)
Karachi: Tfazlani (public domain)
Kinshasa: Themalau (cc by-sa)
Lagos: Jrobin08 (cc by-sa)
London: David Iliff (cc by-sa)
Mexico City: Matthew Rutledge (cc by)
Moscow: Fisss (public domain)
Mumbai: Jasvipul Chawla (cc by-sa)
New York: AngMoKio (cc by-sa)
São Paulo: Tatiana Sapateiro (cc by)
Seoul: Pachinee Buathong (cc by-sa)
Shanghai: J. Patrick Fischer (cc by-sa)
Sydney: Gauthier Pelloquin (cc by-sa)
Teheran: Hamed Saber (cc by)
Tokyo: Cors (cc by-sa)

Mountain ranges quiz
Alaska Range: Jack French (cc by-nc)
Alps: Magnuss (cc by-sa)
Altai Mountains: Dmitry A. Mottl (cc by-sa)
Andes: Victorddt (cc by-sa)
Appalachian Mountains: Ken Thomas (public domain)
Atlas Mountains: Kobersky (cc by-sa)
Caucasus: Grandmaster (cc by-sa)
Drakensberg: Cwawebber (cc by-sa)
Great Dividing Range: Flagstaffotos (cc by-nc)
Himalayas: Daniel Martin (GFDL 1.2)
Hoggar Mountains: B. F. Devouard (cc by-sa)
Karakoram: Florian Ederer (cc by-sa)
Kunlun: Alliance française de Wuhan (cc by-sa)
Maoke Mountains: PJ Riccio (cc by-nc)
Rocky Mountains: T.Voekler (cc by-sa)
Serra do Mar: Jimfbleak (cc by-sa)
Sierra Madre Occidental: Christian Frausto Bernal (cc by-sa)
Taurus Mountains: Alexostrov (cc by-sa)
Tian Shan: Simon Garbutt (public domain)
Ural Mountains: Irina Kazanskaya (cc by)

Mountains quiz
Aconcagua: Mario Roberto Duran Ortiz (cc by-sa)
Ararat: Mediacrat (cc by-sa)
Fitz Roy: Alexandre Ackermans (cc by)
Gunung Kinabalu: Hirosi SBM (public domain)
K2: Maria Ly (cc by-sa)
Mont Blanc: Philippe Kurlapski (cc by)
Mount Cook: Avenue (cc by-sa)
Mount Elbrus: Александр Сорель (cc by-sa)
Mount Everest: Bernard Goldbach (cc by)
Mount Fuji: Alpsdake (public domain)
Mount Kailash: Ondřej Žváček (cc by-sa)
Mount Kilimanjaro: Yosemite (cc by-sa)
Mount Logan: Gerald Holdsworth (public domain)
Mount McKinley: Frank Kovalchek (cc by)
Mount Olympus: Giorgos Kollias (cc by-sa)
Mount Sinai: Tamerlan (public domain)
Mount Tai: AlexHe34 (cc by-sa)
Puncak Jaya: Alfindra Primaldhi (cc by)
Table Mountain: Andreas Tusche (cc by-sa)
Uluru / Ayers Rock: Thomas Schoch (cc by-sa)

Rivers quiz
Amazone River: Lubasi (cc by)
Colorado River: Adrille (cc by-sa)
Congo: Bsm15 (cc by-sa)
Danube: Alan Ford (cc by-sa)
Euphrates: Christiaan Briggs (cc by-sa)
Ganges: Sukalyan Chakraborty (cc by-sa)
Mackenzie: David Adamec (public domain)
Mekong: Allie Caulfield (cc by)
Mississippi: PRA (cc by-sa)
Murray: Mattinbgn (cc by-sa)
Niger: Jialiang Gao (cc by-sa)
Nile: H. Sulzer (cc by-sa)
Rhine: Wolfgang Pehlemann (cc by-sa)
Rio Grande: Andreas F. Borchert (cc by-sa)
Tigris: Bjørn Christian Tørrissen (cc by-sa)
Volga River: Зимин Василий Геннадиевич (public domain)
Yangtse River: Tan Wei Liang Byorn (cc by-sa)
Yellow river: Jucember (cc by-sa)
Yenisei: Oschtan (cc by-sa)
Zambezi: Brian McMorrow (cc by-sa)

Volcanoes quiz
Avachinsky and Koryaksky: Jan van der Crabben (cc by-sa)
Cotopaxi: Paviocko (public domain)
Hekla: Sverrir Thorolfsson (cc by)
Krakatoa: Flydime (cc by)
Mauna Loa: J.D. Griggs (public domain)
Mount Etna: Urban (cc by-sa)
Mount Merapi: Wikipedia (cc by-sa)
Mount Nyiragongo: B.Martinelli (public domain)
Mount Pelée: Jurassi (public domain)
Mount Pinatubo: Wildfire2383 (public domain)
Mount Rainier: Walter Siegmund (cc by-sa)
Mount Saint Helens: Lyn Topinka (public domain)
Mount Vesuvius: Pastorius (cc by-sa)
Nevado del Ruiz: N.Banks (public domain)
Popocatépetl: Jorge 2701 (public domain)
Sakurajima: Roger McLassus (cc by-sa)
Santa María: Worldtraveller (cc by-sa)
Teide: Andys (cc by)
Ulawun: Smithsonian Institute (public domain)
Villarrica: Jonathan Lewis (cc by-sa)