Fortification

Fortifications are military constructions and buildings designed for defense during war. People have constructed defensive works for many thousands of years, but the designs have become more and more complex. The term fortification comes from the Latin words fortis ("strong") and facere ("to make").

Bourtange star fort, restored to 1750 situation, Groningen (province), Netherlands

Many military installations are known as forts, although they are not always fortified. Larger forts may class as fortresses, smaller ones formerly often bore the name of fortalices. Some are castles. The word fortification can also mean the practice of improving an area's defense with defensive works. City walls are fortifications but not necessarily called fortresses.

The last great system of fortification to be built was the Atlantic Wall.