Where is the corbels located in the middle ages castle?

Corbels are not features of castles but are found in churches of the 12th and 13th centuries.

Norman architects knew that rainwater draining from a large roof down the stone walls of a building would be absorbed by the stones, leading to damp entering the building through the walls, and to prevent this the roofs were constructed to overhang the walls by quite some distance.

A series of corbels (supporting stones) would be placed along the top of the wall to support a projecting course which in turn supported the eaves of the roof, meaning that the runoff of water would be clear of the walls.

These corbels offered great opportunities for masons to use their imaginations in carving grotesque faces, mythical animals and comical scenes. These carvings served no useful purpose, they simply decorated the corbels.

See links below for images: