hammer
they were expensive to build
Cheap labor for defensive fortifications.
Medieval castles.
Peasants were not responsible for building castles in Medieval times. Masons and other trained professionals were in charge of making sure castles were built properly.
There is nothing different between todays castles and medieval time castles. Today's castles were built in medieval times.
So that they could be protected during times of war
The welsh medieval castles were big and gray.
Medieval castles were built by local lords who ruled the area. They owned the land, collected taxes and dispensed 'justice'. They required castles to protect themselves from unhappy locals, and sometimes from foreign invaders (depending on the country), and to display their power.
Medieval castles were built out of stone, mortar, and wood.
Castles usually took 7-12 years to build, but bigger ones could take up to 20 years! There would be medieval craftsmen that did masonry, sculpt the huge stone blocks and also architects who would design the castles themselves. Master masons would hire carpenters, glaziers etc. and were highly skilled during the medieval period.
in the late medieval period many medieval castles did have a primitive type of cannon.