medievalcastles.stormthecastle.com

W8V9 TIL the primary purpose of a Castle’s moat was to prevent attackers from tunnelling under the walls.
eKxn TIL Stairwells in medieval castles curved very narrowly and clockwise. Attackers coming up the stairs had sword hands (right hand) against the interior curve of the wall and made it very difficult to swing their swords. Defenders had their sword hands on the outside wall giving much room to swing.