Complex sentence: Ajlun is famous with its castle, also known as castle al-rabadi which was built to protect Ajlun from invaders to protect Ajlun strategic geography from the crusaders as well it was used after the crusades as a home to support the familys of ajlun.
Split into simpler sentences: Ajlun is famous with its castle, also known as castle "al-rabad". The castle was built to protect Ajlun from invaders to protect Ajlun strategic geography from the crusaders as well it was used after the crusades as a home to support the familys of ajlun.