The Sultan Qaboos Grand Mosque is the main Mosque in the Sultanate of Oman. Construction started in 1995 and took six years and four months to complete.
Major features of the interior design are the chandelier (14 meters tall) and the carpet covering the 4,343 square meter area of the prayer hall. It contains, 1,700,000,000 knots, weighs 21 tonnes and took four years to produce making it the world's second largest single piece carpet (#1 belongs to the Sheikh Zayed Grand Mosque in Abu Dhabi).
More info about the mosque: Link