A hilltop castle is a type of hill castle

Hill castle

A hill castle is a castle built on a natural feature that stands above the surrounding terrain. It is a term derived from the German Höhenburg used in categorising castle sites by their topographical location...

 that was built on the summit of a hill or mountain.
The chief advantage of such a strategically selected site was its inaccessibility. The steep flanks of the hill made assaults on the castle difficult or, depending on the terrain, even impossible. In addition, it often commanded excellent fields of view and fire over the surrounding countryside. The sheer height of the castle above the local area could also protect the occupants of the castle from bombardment. In addition, the prominent location of such a castle enhanced its status as a residence.

Nevertheless hilltop castles presented their logistic difficulties. Without sufficiently strong pumps, water supply could be problematic if there was no well in the vicinity. The transport of food, working animals and other goods was also made more difficult by the location and the adverse weather

Weather

Weather is the state of the atmosphere, to the degree that it is hot or cold, wet or dry, calm or stormy, clear or cloudy. Most weather phenomena occur in the troposphere, just below the stratosphere. Weather refers, generally, to day-to-day temperature and precipitation activity, whereas climate...

 usually found on hilltops made living conditions in such a castle less comfortable.

Another problem was the isolation of such castles. The withdrawal of armed foot soldiers into the castle was hampered by the terrain; all the more so for cavalry. Its control over the surrounding region was therefore not always adequate.

The Cathars used a number of inaccessible hilltop castles as refuges, such as Montségur Castle which lies on the summit of a steep rocky mountain.

Like other hill castles, hilltop castles lost their significance during the course of the Middle Ages

Middle Ages

The Middle Ages is a periodization of European history from the 5th century to the 15th century. The Middle Ages follows the fall of the Western Roman Empire in 476 and precedes the Early Modern Era. It is the middle period of a three-period division of Western history: Classic, Medieval and Modern...

. The rise of towns as economic and political centres reduced the value of such castles for trade and governance.