- The Guelta d’Archei is a type of oasis located in the Ennedi Plateau of the Sahara in north-eastern Chad. It is near the town of Fada.
- The water lies concealed in a canyon formed by high cliffs of sandstone that rise up on either side. Rock paintings high up on the cliffs date back to the Holocene Period, c.9,700 BCE.
Gueltas
- A guelta is a dry channel or wadi that either fills with water in the rainy season, or is fed all year round by an underground spring.
Fauna
- The Guelta is the home of the last surviving colony of the West African crocodile in the Sahara. This crocodile is related to the larger Nile crocodile, and feeds on fish found in the guelta.
- Every day herds of camels are brought to the guelta to drink and relax.
Guelta d’Archei, Chad