Just north of the Wahiba Sands and usually visited on your way to or from the desert, Wadi Bani Khalid is considered one of Oman’s most scenic. The gravel track picks a path between date palms as the valley walls close in further and further. Eventually you arrive at a series of emerald-green water pools that are replenished by a stream flowing year-round. The stream disappears up an impossibly narrow crack in the rock, which you can only follow by picking your way along its rim. It’s a popular spot and there are shady pavilions and bridges leading out to rocky outcrops in the pools.