Located between 10° and 12°S latitude and 44° and 46°E longitude, the Comoros are at the northern end of the Mozambique Channel approximately halfway between Madagascar and Mozambique. They are an archipelago of four islands and several islets with an area of 785 square miles (2,034 square kilometers). Of volcanic origin, the Islands arose from a fissure in the seabed running northwest – southeast. The oldest island, Mayotte, is located southeast of the youngest island, Grande Comore, which still has an active volacano.
The four islands are Ngazidja (Grande Comore), Mwali (Moheli), Nzwani (Anjouan), and Maore (Mayotte). Ngazidja is the largest and most westerly of the islands, lying 188 miles from Mozambique. It is also the youngest island in the archipelago having emerged from the seabed only about 10,000 years ago. Karthala is the name of the active volcano that dominates the southern half of Ngazidja. It rises to a height of 7,746 feet (2,361 meters) above sea level. Karthala has the largest caldera of any volcano in the world and has produced numerous lava flows including some that reached the sea in recent times and are clearly visible today. Mwali, 28 miles south-southeast of Ngazidja, is the smallest of the islands with a central mountain range that rises 2,556 feet (790 meters) above sea level. Nzwani lies about twenty-five miles easterly of Mwali, has a central peak that rises 5,072 feet (1,575 meters) above sea level. It has rugged mountains and swift running streams with waterfalls that cascade down to long, black, sandy beaches. Forty-four miles to the southeast of Nzwani is Maore, the oldest of the four islands. Approximately 8 million years old, it is comparatively flat, has slow meandering streams, and is almost completely surrounded by a well-developed barrier reef.