685-2899 - Tilbury Fort, Tilbury, Essex, England, United Kingdom, Europe

685-2897 - Tilbury Fort, Tilbury, Essex, England, United Kingdom, Europe

1358-490 - Fort St. Catherine, built in 1614 to defend sea approaches to the island, now a museum, UNESCO World Heritage Site, St George's, Bermuda, Atlantic, North America

1243-562 - A weathered stone fort and Portuguese flag flying from flagpole on a small turret, Lisbon, Portugal, Europe

1184-12642 - Cite de Carcassonne citadel, UNESCO World Heritage Site, Carcassonne, Aude, Occitania, France, Europe

796-2664 - Montjuic Castle old military fortress on Montjuic Mountain overlooking the city, Barcelona, Catalonia, Spain, Europe

1235-2323 - Aerial view of Venetian Fortezza Castle, Rethymno, Crete, Greek Islands, Greece, Europe

1384-1205 - Historic castle in Alter do Chao, built in the 14th century, Alentejo, Portugal, Europe

1384-1197 - Defensive walls and ramparts with view over surrounding countryside from the Castle of Terena, a listed national monument, Terena, Alentejo Central, Portugal, Europe

1384-1194 - Cannon in historic castle in medieval village of Marvao, Portalegre district, Alto Alentejo, Portugal, Europe

1384-1191 - Historic castle, medieval village of Marvao, Portalegre district, Alto Alentejo, Portugal, Europe

1384-1187 - Historic walled castle in hilltop village of Monsaraz, Alto Alentejo, Portugal, Europe

1184-12276 - Castel Nuovo, the historic Centre of Naples (Napoli), UNESCO World Heritage Site, Campania, Italy, Europe

1384-1126 - Cannons on ramparts of citadel castle Il-Kastell, Victoria Rabat, Gozo, Malta, Mediterranean, Europe

1384-1099 - Historic waterfront buildings on Grand Harbour waterside, Valletta, Malta, Mediterranean, Europe

1184-12162 - Fort of San Sebastian, Island of Mozambique, UNESCO World Heritage Site, Mozambique, Africa

1385-320 - Medieval stone tower on a grassy hill with clear blue sky, flanked by church spires in the background, Clifford's Tower, York, North Yorkshire, England, United Kingdom, Europe

1384-358 - Historic defensive buildings, Rampart Mogador, Essaouira, Morocco, North Africa, Africa

1384-263 - Spanish colonial fortification, Fort de San Felipe, Bacalar, Quintana Roo, Yucatan Peninsula, Mexico, North America

1384-260 - Spanish colonial fortification, Fort de San Felipe, Bacalar, Quintana Roo, Yucatan Peninsula, Mexico, North America

1384-257 - Spanish colonial fortification, Fort de San Felipe, Bacalar, Quintana Roo, Yucatan Peninsula, Mexico, North America

1384-44 - Puerta de Tierra gateway entrance, Fortifications, Spanish military architecture of city walls, Campeche City, UNESCO World Heritage Site, Campeche State, Mexico, North America

1384-39 - Puerta de Tierra gateway entrance, Fortifications Spanish military architecture of city walls, Campeche City, UNESCO World Heritage Site, Campeche State, Mexico, North America

1384-38 - Fortifications Spanish military architecture of city walls, Campeche city, Campeche State, Mexico, North America

1384-37 - Fortifications, Spanish military architecture of city walls, Campeche City, UNESCO World Heritage Site, Campeche State, Mexico, North America

832-402044 - View through a keyhole in the castle walls onto parts of the outer castle complex, Hohenrechberg Castle near Schwaebisch-Gmuend, Baden-Wuerttemberg, Germany, symbolic image, Europe

832-400223 - Stone guardhouse on the walls of an old colonial-style fort on the seafront of Salvado in Bahia, Brasil

832-400222 - Old iron cannon and guardhouse on the strong walls of the historic fortress of Farol da Barra in the city of Salvador, Bahia, Brasil

832-400220 - Interior of an old colonial style fortress and one of the main tourist attractions in the city of Salvador in Bahia, Brazil, Brasil, South America

832-400191 - Old historic fort and colonial guardhouse with cannon pointed to the sea in the city of Salvador in Bahia, Brasil

832-400190 - Guardhouse and lookout in an old historic fortress in the city of Salvador in Bahia, Brasil

1351-223 - Ananuri Fortress, on the Military Highway from Tbilisi to Kazbegi, Georgia (Sakartvelo), Central Asia, Asia

1113-107283 - Firing historic cannons at Fort Henry Historic Site and Museum of Living History with uniformed performers known as the Fort Henry Guard performing British military life demonstrations and tours for visitors, Kingston, Ontario, Canada, North America

1113-107198 - Firing historic cannons at Fort Henry Historic Site and Museum of Living History with uniformed performers known as the Fort Henry Guard performing British military life demonstrations and tours for visitors, Kingston, Ontario, Canada, North America

1113-106913 - Uniformed performers known as the Fort Henry Guard lead British military life demonstrations and tours for visitors to Fort Henry Historic Site and Living History Museum, Kingston, Ontario, Canada, North America

1245-2293 - Castell de Sant Ferran (Sant Ferran Castle), a large military fortress, Figueres (Figueras), Catalonia, Spain, Europe

832-383594 - Vietnamese sentries in front of the noon gate, changing of the guard, citadel Hue, imperial palace Hoang Thanh, Hue, Vietnam, Asia

832-379129 - Hohenzollern Castle, Zollernalbkreis, Swabian Jura, Baden-Wurttemberg, Germany, Europe

776-5119 - Harding's Battery, Europa Point, Gibraltar, United Kingdom, Europe

776-5107 - Harding's Battery, Europa Point, Gibraltar, United Kingdom, Europe

776-5120 - Harding's Battery, Europa Point, Gibraltar, United Kingdom, Europe

746-88185 - View over the town with the fortifications of Fort Santa Luzia, the greatest preserved fortification worldwide dating back to the 17th century.Elvas in the Alentejo close to the spanish border. Elvas is listed as UNESCO world heritage. Europe, Southern Europe, Portugal, March

746-88177 - Bastions proctecting the Portas de Olivenca. Fort Santa Luzia, the greatest preserved fortification of the 17th century worldwide. Elvas in the Alentejo close to the spanish border. Elvas is listed as UNESCO world heritage. Europe, Southern Europe, Portugal, March

797-10858 - England, Hampshire, Milford on Sea, Second world war defences at Hurst Castle to defend the strategically important Solent.

797-10859 - England, Hampshire, Milford on Sea, Second world war defences at Hurst Castle to defend the strategically important Solent.

832-279568 - Triva tower, Klenzepark, Bavarian army museum, Ingolstadt, Bavaria, Germany

832-246637 - The fort of "Castillo de San Carlos Borromeo", Spanish military architecture, Pampatar, Margarita Island, Caribbean, Venezuela, South America

1161-6483 - Tintern Abbey 12th Century, formerly a Cistercian Abbey, in County Wexford built by Earl of Pembroke in 1200, Ireland

1161-6482 - Tintern Abbey 12th Century, formerly a Cistercian Abbey, in County Wexford built by Earl of Pembroke in 1200, Ireland

832-127105 - Nave, Ananuri Fortress, Church of the Ascension, Aragvi Valley, Georgian Military Road, Caucasus, Georgia, Middle East

832-127103 - Fortress Ananuri with Redeemer Church and Church of the Assumption at the Ananuri Reservoir, Ananuri, Aragvi Valley, Georgian military road, Caucasus, Georgia, Eurasia

832-126179 - Cannon and loop-hole, Ciudad Velha, Cidade Velha, island of Santiago, Cabo Verde, Africa

832-127104 - Fortress Ananuri with Redeemer Church and Church of the Assumption at the Ananuri Reservoir, Ananuri, Aragvi Valley, Georgian military road, Caucasus, Georgia, Eurasia

832-126942 - Church of the Assumption and defence tower, the upper castle of Ananuri Fortress, Shinwali, Georgian Military Road, Georgia, Western Asia

832-52768 - Former Defensionskaserne barracks, Festung Petersberg fortress, Erfurt, Thuringia, Germany, Europe

832-52767 - Former Defensionskaserne barracks, Festung Petersberg fortress, Erfurt, Thuringia, Germany, Europe

1116-8640 - 16Th Century Castillo De La Real Fuerza; Havana, Cuba

831-941 - St. Mawes Castle, an artillery fortress built by Henry VIII, Cornwall, England, United Kingdom, Europe

752-37 - San Jeronimo Fort San Juan Puerto Rico