Khatmiya is the oldest neighbourhood of Kassala and the historical headquarters of the Khatmiyya Sufi brotherhood, founded in the early 19th century. The mosque sits dramatically against the base of Jebel Taka, with one wall continuing into the natural rock face. It is roofless, by design or accident depending on who you ask, and visitors are welcome inside if they are dressed modestly.
Adjoining the mosque is the small whitewashed tomb of Sayyid Hassan al-Mirghani, the founding sheikh's son and one of the most revered figures of the order. Visitors are sometimes invited inside; ask quietly and follow your host's lead.
A short walk away is a tariqa belonging to the Burhaniya, another Sufi order. On Friday evenings towards sunset the brotherhood gathers to chant the dhikr to a steady drumbeat — one of the most atmospheric experiences in this part of Sudan.