The end result was a strong fortification system of three concentric fortress chains.

The equipment creation and fortification systems received a variety of changes.

The main fortification system grew toward the north, the only possible direction where an attack could come from.

The first works of the new French fortification system were launched in 1874.

The fortification system was maintained and upgraded during the Cold War.

Outside of the town walls the fortification system was completed by a moat.

Various military buildings were constructed and in 1876 reconstruction of the fortification system was completed.

The town had a complex fortification system and was completely built up.

The fortification system continues on the other side of the water in the Christianshavn city district.

The town was protected by a sophisticated semicircular fortification system.