The Sur Al Lawatia tower is the only remaining tower of an original four defensive towers that once surrounded the walled neighborhood enclave of Sur Al Lawatia in old town Muttrah in Muscat. Amounting to about 200 to 300 houses, Sur Al Lawatia is a small Shiite community occupied by the traditionally merchant tribe of Al Lawatia, which arrived in Oman in the 17th century and settled next to the Matrah Souq, and allegedly the former site of a Portuguese garrison. This community still lives in the neighborhood location and remains relatively secluded. Access to Sur Al Lawatia is only possible through one of two doors - a front gate and rear gate. Outsiders are generally not allowed to enter the enclave, and those that attempt to do so (without an escort) are usually turned away by someone stationed at the entrance. Next to the neighborhood's front entrance on the Muttrah Corniche is Oman's main Shia mosque, Musjid Al-Rasool Al-A'dham (مسجد الرسول الاعظم).