Medieval toilets were built into the walls of castles
Indoor plumbing revolutionized toilets. However, this does not mean there were no functional waste disposal systems in the past. Latrines, or “privies,” as they were often called in Medieval times, had a unique design. They were usually built into the walls and could be seen while projecting from the outside.
The waste usually fell into the castle moat below or into a river, which then washed everything away. Other castles had tiers of toilets on the outside wall with shafts that sent all waste to the same collection point. Some of these reached almost to the ground, and besiegers sometimes took advantage of those to invade.