Start where the road turns to dirt at the end of setti fadma, past all the villages. Take the dirt road all the way back, about 20 km, until you summit the pass Tizi N'Tacheddirt. It's a long, gradual uphill on the road past very remote terrain and remote villages, until you reach the national park trail. Soon, it gets steep as you gain more and more altitude. variations summit and back, or summit and over, can be done. Be prepared to carry everything you need for the full run, not really any opportunity for water or resupply. Incredible place.
the there-and-back variation is almost perfectly marathon distance.
