The Richat Structure

The Richat Structure, Guelb er Richat, is a set of concentric rock rings some forty kilometres across, conspicuous enough from orbit that astronauts used it as a landmark from the early missions. Geologists describe it as an eroded dome rather than an impact crater: rings of resistant rock left standing as softer layers wore away, with details still debated. On the ground the rings become a landscape of ridges, gaps and gravel plains crossed by 4x4 tracks from Ouadane, with camps among the ridges.

What's there

• The ring ridges - concentric rock ridges crossed by the tracks.
• The central dome - the core of the structure.
• The rim viewpoints - the structure's curve read from high ground.
• The desert camps - nights inside the rings.

When to go

November to February for workable temperatures; the structure reads best in low morning and evening light when the ridges shadow. It folds into the Ouadane day or an overnight camp.

Practical notes

At ground level the rings cannot be seen whole - that needs satellite imagery or a drone - and a guide who explains the geology adds a great deal. Standard deep-desert rules: convoy or experienced driver, water margins, no improvising.

Nearby

Ouadane's ksar, the Adrar pistes and Atar.

Key facts