The island of Antsoheribory is situated in the Baie de Boina, some three hours by boat from Mahajanga to the west along the coast. The island houses a huge number of well preserved, and fascinating remains from a town that goes back to the Middle Ages, probably being the forerunner of Mahajanga. The town goes under the name Masselage, and was finally abandoned in the beginning of the 18th century, and after that, the island has been uninhabited, except for occasional visits by fishermen and sheppards.
The island houses impressive remains of houses, mosques, and tombs, and other structures, rather well preserved. The ground is strayed with traces of settlement in the form of beads, pottery and pieces of glass vessels.