| They were built as a system of separate fortresses, abatis lines, and on forested terrain, tree blowdowns. |
| Within the bustling capital is Old Havana, a walled city of 143 hectares with three military fortresses. |
| World War I saw the evolution of a new fortification setup combining field strongholds with fortresses. |
| They lost a string of fortresses, and the province of Holland was only saved by a man-made flood when the dykes were deliberately opened. |
| City walls, towers, churches, and fortresses strongly connect Estonians to the past. |
| They have inherited the military fortresses that are described as police stations. |
