Ajloon Castle

Saladin had this castle built by the great engineer Murhanideen (sp?) to defend against the Crusaders in the 11th century.
So impregnable were its walls that even the Mongols - who sacked Baghdad- couldn't take it. Its secret? Our tour guide (also the castle's archaeologist) showed us its moat, primitive grenades made from salt-peter and animals skins launched via catapult, arrow slits, places for dumping boiling oil on would-be siegers, 4000 cubic meters of water storage collected from a vast network of channels surrounding the castle, and a multi-colored chemical flare system that enabled its inhabitants to communicate with nearby garrisons and receive reinforcements. They even burned medicinal herbs to impart chemical compounds in the water to prevent it from becoming unpotable.