The stone circle at Mzoura is generally believed to have been the grave of a Mauritanian king around 3000 BCE. It consists of 167 standing stones forming a diameter of about 60 meters. What was inside the circle is an open question. The grave is best presented in the archaeological museum in Tetouan, where there is a small model of it.
Practicalities
Getting out to Mzoura is a challenge, and will normally involve the use of a local guide. Having an Asilah taxi drive you, is quite difficult. Few see the point of destroying their cars, even for a good tip.