Located on the southern half of Île Ste.Hélène(the second largest island that makes up St.Anaïs) the départissement of Martineau is primarily a region known for its secluded beaches and lush forests. Due to the shape of the area Martineau boasts excellent port facilities which makes it a hub of ocean traffic. The two main settlements in Martineau are Calienne and St.Marcel. Although the départissement does not have as many tourists as on the main island (Île St.François) it is popular for its nightlife in Calienne and the beautiful beaches.

The city of Calienne is the second largest in the country after Franceville. It is primarily a centre for trade and commerce thanks to its port facilities. It has a population of 3600 people

The town of St.Marcel serves primarily as a commuter town for people who work in Calienne. It is located 6 kms from the city.