Small Castles (Keep Castles)
- Square keep castles, also known as tower keeps or pele towers, were relatively small in size and designed as strong fortified towers for defense.
- They typically had a square or rectangular layout and ranged from around 30 to 40 feet (9 to 12 meters) in width and height.
Medium-Sized Castles:
- Motte-and-bailey castles were common during the early medieval period. They consisted of a raised earthen mound (motte) with a wooden or stone tower on top, surrounded by a fortified courtyard (bailey).
- The motte could range from 100 to 150 feet (30 to 45 meters) in diameter, and the bailey often covered several acres.
Large Castles:
- Royal castles and large aristocratic castles often featured massive fortifications, extensive walls, and multiple towers and buildings within their complexes.
- They could cover several acres of land and might include structures like great halls, chapels, kitchens, barracks, workshops, and more.
- The Tower of London, for instance, occupied an area of around 18 acres (7.3 hectares).
Concentric Castles:
- Concentric castles, characterized by multiple layers of defensive walls arranged in concentric circles, could be extremely large.
- Caerphilly Castle in Wales, for example, has three concentric rings of walls with a diameter of around 1,000 feet (305 meters) for the outermost ring.
It's important to note that the castles mentioned above are just a few examples, and there were many different types and sizes of castles built during the medieval period, ranging from small fortified keeps to vast and complex complexes.