This hike begins with a boat ride across the deep water at the wadi's entrance, organised by enterprising locals, and continues through plantations, crisscrossing the wadi several times before reaching a small pumping-station. Be prepared to wade up to your knees in places and beware of slipping on algae-covered rocks. After heavy rains, bring a bag for your camera and dry clothes.
The path has been concreted (not very sympathetically) for part of the way and passes close to several villages that are hidden in the plantations. At times the path follows an impressive falaj (traditional irrigation system) complete with underground sections and laced with ferns. The wadi eventually broadens into an area of large boulders and wild fig trees with many pools of deep water. Look for a ladder descending into one of these pools as Wadi Shab bends to the left. If you duck through a short underwater channel in this pool, you will find the partially submerged cavern. Allow up to two hours of walking to reach this pool.
It’s possible to walk beyond the pools to other small villages clustered along the wadi floor but the paths are not so well-trodden and they follow, sometimes steeply, goat tracks over the wadi cliffs. Walking shoes and plenty of drinking water are necessary. The wadi becomes drier the higher you climb into the mountains.