Oman's sightseeing is anchored by cultural investment that the country's low-rise modesty doesn't immediately suggest. The Grand Mosque, open to non-Muslim visitors on weekday mornings, holds the world's second-largest hand-knotted carpet in a prayer hall of marble and pietra dura inlay. The oldest souk in the Gulf carries frankincense, silver jewellery, and traditional daggers in a covered bazaar that smells of incense and cedar. The national museum of heritage and the decorative arts museum provide the historical depth. Nizwa Fort and souk, the ancient irrigation system UNESCO sites, and the Wadi Ghul canyon extend the circuit into the heartland of traditional Omani culture. Tours by locals add the missing layer. Take it all in.