Series: Fortress

Hindenburg Line

Walls of Constantinople AD 324–1453

Fortifications in Wessex c. 800–1066

Afghanistan Cave Complexes 1979–2004

Japanese Pacific Island Defenses 1941–45

Norman Stone Castles (2)

Indian Castles 1206–1526

US Strategic and Defensive Missile Systems 1950–2004

English Civil War Fortifications 1642–51

Troy c. 1700–1250 BC

Forts of the War of 1812

German Fortress of Metz 1870–1944

Scottish Baronial Castles 1250–1450

Führer’s Headquarters

English Castles 1200–1300

Crusader Castles in the Holy Land 1192–1302

Norman Stone Castles (1)

U-Boat Bases and Bunkers 1941–45

Fortifications of the Incas

Castles of Henry VIII

Forts of the American Revolution 1775-83

Lines of Torres Vedras 1809–11

Defense of the Rhine 1944–45

Fort Eben Emael

Atlantic Wall (2)

Japanese Castles 1540–1640

Japanese Castles in Korea 1592–98

Crusader Castles of the Teutonic Knights (2)

Spanish Colonial Fortifications in North America 1565–1822

Great Wall of China 221 BC–AD 1644

Fortresses of the Peninsular War 1808–14

Hittite Fortifications c.1650-700 BC

Cathar Castles

Forts of the American Frontier 1776–1891

Defenses of Pearl Harbor and Oahu 1907–50

Fortifications of the Western Front 1914–18

Strongholds of the Border Reivers

American Civil War Fortifications (1)

Roman Legionary Fortresses 27 BC–AD 378

Roman Auxiliary Forts 27 BC–AD 378

Forts of New France

Channel Islands 1941–45

Spanish Main 1492–1800

Forts of the American Frontier 1820–91

German V-Weapon Sites 1943–45

British Forts in the Age of Arthur

Atlantic Wall (3)

Vietnam Firebases 1965-73

Crusader Castles of the Teutonic Knights (1)

Castles and Tower Houses of the Scottish Clans 1450–1650