By Mohamed El-Hebeishy YOU MUST have passed it driving down Cairo's Autostrade. Not more than a kilometre or two from the Citadel in the direction of Maadi, it is on your left, a mosque in ruins that still hangs by a thread on the steep cliffs of Moqattam Hills. Mohamed El-Hebeishy tries to decipher the mysterious . His name is Sheikh Al-Salih Al-Abid Shahin Al-Khalawati, a pious man who was born in Tabriz (present- day Iran). At an early stage of his life he joined the army of Sultan Qaitbey. Military life did not entice Al-Khalawati and so he requested that he be granted his release from the army for a more spiritual life, devoting himself to religion. He returned to his hometown Tabriz joining Sidi Omar Rawshani, who initiated him into the Khalawatiya order. Later, Shahin went again to Cairo joining another great scholar, Mohamed Al-Demerdashi. After Al-Demerdashi's death, Shahin Al-Khalawati took refuge in the hills of Moqattam, building himself a place of worship that later contained his grave as well. It is said that he stayed in the hills for 30 years; not once did he descend to Cairo. Built in 1533 AD, is nicknamed the Castle of Mamelukes. Shahin himself was a man of virtue and that gained him the love and respect of almost everyone who met him. Though his mosque was and still is quite difficult to access, Shahin had received princes and viziers, in addition to numerous followers of the Khalawatiya order. According to historian Ira Lapidus, the core concept behind Khalwatiya emphasises "the importance of combining hadith and law with Sufi asceticism and meditation in opposition to shrine worship and festivals". Khalawatiya derives from the Arabic word khalwa which refers to one's withdrawal for spiritual communion. Currently, Shahin is not only out of order but also a dangerous place to visit as it is in danger of collapsing. Rediscovering it is adventurous but risky.