The Friday mosque of In-Gall is built in the traditional Sahelian mud-brick style — a single low rectangular hall with a flat earthen roof supported on palm-trunk beams, a square minaret with projecting palm-wood stakes used as scaffolding for the annual replastering, and a small open courtyard for ablutions. The current structure is largely twentieth-century but follows a layout that has been on this site for centuries.
The mosque is the centre of religious life in the town, and the imam's authority extends across the Tuareg encampments of the surrounding plain. Non-Muslims may not enter, but the exterior is one of the most photographed buildings of central Niger and the courtyard is open to view from the street.