Encircled by beds of delicate flowers and small trees, this mosque invites worshippers to rediscover tranquillity as if they were walking in a 6th-century Persian garden. With the western Al-Hajar Mountains a heartbeat away, the experience feels both outdoor and indoor. Inside the main prayer hall, you can walk upon the world’s second-largest handmade rug. Visitors are welcome in the mornings until 11 a.m. and are reminded to dress modestly.