Ilha da Inhaca is a subtropical island of Mozambique off the East African coast. The 52 km2 island separates Maputo Bay to the west from the Indian Ocean off its eastern shores. The island's irregular coastline approaches mainland Machangulo Peninsula at Ponta Torres where a 500-metre-wide tidal race separates the two headlands. The highest point above sea level is the 104-metre Mount Inhaca on the north-eastern shoreline. The south-western peninsula is known as Ponta Punduine while Ponta Torres to the south-east approaches the mainland. Two inland swamps occur at the northerly airstrip and southern Nhaquene respectively. Besides Inhaca settlement on the western shore there are five smaller villages including Inguane, Nhaquene, Ridjeni and Tobia. Despite being a part of the Portuguese Colony of Mozambique until 1975, the island of Inhaca, so close to the harbour of Maputo, was occupied by the British from 1823 until the Mac Mahon Treaty of 24 July 1875. The British used the island (amongst many others all around Africa) to patrol and control the slave traffic in the region.