he locations chosen for the construction of a fortress are varied: on an inaccesible high cliff beside a fountain or a well, by a ford or a bridge over a river, near a plain, or even in a water course to get shielded from artillery in a deep moat.

The relationship of castles with towns or cities is also varied. If the town has been born by the castle, the town gets to surround it all. So, the castle occupied the central site, which had a great representative value, but was also dangerous from the defensive point of view, especially if the loyalty of the town inhabitants was not certain.

The castles that were built ex-novo on previously fortified towns, were always embedded in the walls, not only to buttress the defence of the town, but to have an independent entry to the castle as well.

The use of artillery obliged to clear wider and wider areas around the fortresses, so country houses, convents, churches, etc. had to be pulled down.