As with other 11th-13th-century castles, the early medieval improvements and development of Marvão castle reflect the innovations brought back by crusading orders from the near east (notably the highly influential Hospitaller castle in Syria, the Krak des Chevaliers). The medieval castle seen in Marvão today mostly post-dates the year 1299, and features numerous characteristic features of a crusader-era castle: a tall central keep with raised entrance on the first floor; a series of lower, outlying turrets (some semi-circular); high-placed arrow-slits; open spaces to aid the sheltering and assembly of villagers and troops; a well, and huge rain-collecting cistern to supply water to both keep and the wider castle in the event of siege; bent entrances (both on the village and castle gates) to slow down invaders in the event of breached gates; a series of narrow killing zones (notably, in the triple gate on the village-side of the castle); extensive crenellated battlements and curtain walls that enhanced the natural defences provided by the escarpments of Marvão's rock.[32]