At over 20m wide and 230m deep, the Gouffre du Friouato is said to be the deepest cavern in North Africa, and the cave system is possibly the most extensive. In 2016 a section of the roof collapsed, killing some schoolchildren, and at the time of writing the caves were still closed – ask in Taza before heading out here. A return grand taxi from Taza Haute costs Dh200 upwards – depending on how much time you want in the caves.
Gouffre du Friouato is well signposted, up a very steep road 25km from Taza. It was first investigated in 1935 and access is via 520 precipitous steps (with handrails) that lead you to the floor of the cavern. It’s a strenuous climb back up. At the bottom, you can squeeze through a hole to start exploring the fascinating chambers that are found 200 more steps below. It’s dark and eerily beautiful: wear clothes you don't mind dirtying.
The most spectacular chambers, full of extraordinary formations, are the Salle de Lixus and the Salle de Draperies. They do indeed resemble thin sheets of curtains, frozen and calcified. Allow at least three hours there and back. Speleologists have explored to a depth of 300m, but they believe there are more caves another 500m below.
The admission fee allows you to enter the cavern mouth at a depth of 160m. Beyond that, a guide is needed to go further underground to the grandest chambers. Bank on the occasional scramble, and squeezes through narrow sections; not recommended for claustrophobes. Overalls, nonslip overshoes and a helmet with lamp must be rented.