Sultan qaboos grand mosque opening hours If you are ever in Muscat, you cannot miss its magnificent Grand Mosque. The main mosque in the Sultanate of Oman is breathtakingly beautiful, to say the least. Commissioned in 1992 to mark the 30th anniversary of Sultan Qaboos''s reign, the mosque was completed in 2001. It is one of the only mosques in Oman that allows non-muslims in the.