What is dry moat?

A dry moat is a defensive feature that was commonly used in medieval fortifications. It is a deep trench that surrounds a castle or fortress, and it serves to hinder attackers from reaching and scaling the walls. Unlike a wet moat, which contains water, a dry moat is usually empty and can be crossed using bridges or other means. The presence of a dry moat also creates a clear line of sight around the fortification, which can make it more difficult for attackers to approach unseen. However, dry moats can also be a disadvantage if the defenders are unable to exit the fortification to fight off an attack or if attackers are able to fill the moat or use it for cover.