The minaret of the Grande Mosquée (closed to non-Muslims) is studded with jutting wooden sticks, in the style of Sahel mosques including the famous Djinguereber Mosque in Timbuktu, Mali. Local legend suggests this is where the souls of the dead congregate. More likely, these were left in place by the masons who built the minaret to help them climb up and replaster. There's a very atmospheric single palm standing in the small square at the mosque's entrance.
Recently added signage – in French, Arabic and Tifinagh – explains the history of the mosque.