The Comoros is a volcanic archipelago off Africa's east coast, in the warm Indian Ocean waters of the Mozambique Channel. The country state's biggest island, Grande Comore (Ngazidja) is ringed by shorelines and old magma from dynamic Mt. Karthala fountain of liquid magma. Around the port and medina in the capital, Moroni, are cut entryways and a white colonnaded mosque, the Ancienne Mosquée du Vendredi, reviewing the islands' Arab legacy.