Grand Husseini Mosque is one of the oldest mosques in Amman and one of the main landmarks of the downtown area. Originally built in 640 AD during the reign of the second Caliph Omar ibn al-Khattab on the probable site of Roman Philadelphia's cathedral. The current mosque was rebuilt in 1924 by King Abdullah I using striking pink-and-white stone in Ottoman style. One 13-meter tall minaret was added in 1924, a second in 1952. Major expansion and restoration occurred in 1987 under King Hussein. The mosque now accommodates 2,600 worshippers across 2,000 square meters. It sits in the heart of downtown souq district, surrounded by vibrant markets.