31. Arrow slits , concealed doors for sallies, and deep water wells were also integral to resisting siege at this time.32. A covered walkway with arrow slits went along the top of walls and above the walls nine powerful towers were raised. 33. The towers were built on three levels with arrow slits in each level and basements below, which have survived intact. 34. The two massive Ayyubid defense towers were built with thick stone walls into which the deep arrow slits were discreetly inserted. 35. There are small square windows on the south side facing the creek; all of the other openings are arrow slits . 36. The southern side had seven rooms with 52 arrow slits , and the northern side had five rooms with 21 arrow slits. 37. The southern side had seven rooms with 52 arrow slits, and the northern side had five rooms with 21 arrow slits . 38. The watchtowers at Guang'anmen, Guangqumen, Zuo'anmen, and You'anmen each had 22 arrow slits . 39. From the outside, the Palace of Europe resembles a fortress, since the rows of windows are arranged like arrow slits . 40. It had battlements and turrets, arrow slits , window panes in the gothic style, and was topped with a crest.
