Constantinos Petrinos / Fasilides Castle, ruined fortress city founded in the 17th century. Amhara National Regional State, North Gondar Administrative Zone, Ethiopia, Africa, March 2009

Axel Gomille / Panoramic of the city of Jaisalmer, nicknamed the Golden City, view of the fort from Gadisar Lake, Thar Desert, Rajasthan, India. February 2012.

RHONDA KLEVANSKY / Canon lighting ceremony at sunset, Fort, Santiago de Cuba, Cuba, November 2011.

Rhonda Klevansky / Four people in traditional costumes lined up against wall, part of a Canon lighting ceremony at sunset, Fort, Santiago de Cuba, Cuba, November 2011.

David Woodfall / Army and police in flooded street after February 2014 flooding, helping to provide support for the residents and supplying sand bags, Chertsey, Surrey, England, UK, 16th February 2014.

Colin Varndell / Ramparts on west end of Hambledon Hill prehistoric hill fort, Dorset, UK. June 2013

Colin Varndell / West entrace to Maiden Castle iron age hillfort near Dorchester, Dorset, UK. June 2013

Franco Banfi / Castello / castle Aragonese, on island off Ishcia, Italy, Tyrrhenian Sea, Mediterranean

Franco Banfi / Castello / castle Aragonese, Ischia Island, Italy, Tyrrhenian Sea, Mediterranean

Bryan and Cherry Alexander / Remains of a wooden building at a prison camp from the Stalin era near Yarudey. Yamal, Western Siberia, Russia, February 2009.

Bryan and Cherry Alexander / Outdoor exhibits at the museum in Stanley, Falkland Islands, 2009.

Luiz Claudio Marigo / Castillo de San Felipe de Barajas (San Felipe de Barajas Fortress), the largest military construction of Spanish colonial times in South America in Cartagena de Indias, a UNESCO World Heritage City. B...