Ajlun is located 73 km north of Amman, and a short journey northwest from Jerash,
through a beautiful pine-forest and olive groves, brings you to the town of Ajlun.
The castle was conceded in the 13th century to Salah al-Din Yousef Ibn Ayoub, ruler of Aleppo and Damascus, who restored the northeastern tower. These expansion efforts were interrupted in AD 1260, when Mongol invaders destroyed the castle, but almost immediately, the Mameluk Sultan Baybars.
The original castle had four towers; arrow slits incorporated into the thick walls and it was surrounded by a moat averaging 16 meters in width and up to 15 meters deep.
Nearby is the Ajlun Nature Reserve, a 13 square kilometre protected area of outstanding beauty and diverse wildlife. Within the reserve are two nature trails and chalet-style accommodation. The reserve is managed and maintained by the Royal Society for the Conservation of Nature (RSCN).