1     Japanese Pacific Island Defenses 1941-1945
2     Hadrian's Wall 122-410 AD
3     U-Boat Bases and Bunkers 1941-1945
4     American Defenses of Corregidor and Manila Bay 1898-1945
5     Japanese Castles 1540-1640
6     American Civil War Fortifications (1) : Coastal Brick and Stone Forts
7     The Lines of Torres Vedras 1809-1810
8     Defenses of Pearl Harbor and Oahu 1907-1950
9     English Civil War Fortifications 1642-1651
10    The Maginot Line 1928-1945
11    Crusader Castles of the Teutonic Knights (1) : The Red Brick Castles of Prussia 1230-1466
12    Fortresses of the Peninsular War 1807-1814
13    Norman Stone Castles (1) : The British Isles 1066-1216
14    Fortifications in Wessex c. 800-1066 : The Defenses of Alfred the Great against the Vikings
15    Germany's West Wall : The Siegfried Line
16    The Fortifications of Malta 1530-1945
17    Troy c.1700-1250 BC
18    Norman Stone Castles (2) : Europe 950-1204
19    Crusader Castles of the Teutonic Knights (2) : The Stone Castles of Latvia and Estonia 1185-1560
20    British Home Defences 1940-1945
21    Crusader Castles in the Holy Land 1097-1192
22    Mycenaean Citadels c. 1350-1200 BC
23    German Field Fortifications 1939-1945
24    Fortifications of the Western Front 1914-1918
25    The Walls of Constantinople AD 324-1453
26    Afghanistan Cav Complexes 1979-2004:  Mountain Strongholds
27    French Fortresses in North America 1535-1763:  Quebec, Montreal, Louisbourg and New Orleans\
28    Forts of the American Frontier 1820-91:  Central and Northern Plains
29    US World War II and Korean War Field Fotifications 1941-53
30    Fort Eben Emael:  The Key to Hitler's Victory in the West