Chien Lee / Travellers Palm (Ravenala madagascariensis) trees on hillside, Fianarantsoa Province, Madagascar

Ernie Janes / Abstract photo of Tower Bridge, with blurred motion red bus, London, June 2013. Digitally manipulated.

Laurent Geslin / Man selling Massala chai (tea) to travellers at Bharatpur railway station, Rajasthan, India 2006

Andy Rouse,Andy Rouse / Ring tailed Lemur (Lemur catta) mother carrying baby on back. Madagascar.

Phil Savoie / Travellers palm (Ravenala madagascariensis) close up of leaf intersections, Costa Rica.

Phil Savoie / Travellers palm (Ravenala madagascariensis) clos up, Costa Rica.

Tom Gilks / Bicycle taxis with passengers carrying people, Kisumu, Kenya, February 2013.

Tom Gilks / View from the back of a Matatu mini van taxi, Kenya. February 2013.

Ingo Arndt / Travelers Palm (Ravenala madagascariensis) close-up view of fronds, Christmas Island, Indian Ocean, Australian Territory

Ingo Arndt / Travelers Palm (Ravenala madagascariensis) close-up view of fronds, Christmas Island, Indian Ocean, Australian Territory

Tim Laman / National Geographic Explorer walking along path on New Island, Falkland Islands, March 2011.

Kristel Richard / Marbach staff in traditional uniform driving four Wurttemberg stallions during the stud's 500th anniversary celebrations. Marbach National Stud, Swabian Alps, near Reutlingen, in Baden-Wurttemberg, Ge...