From largest to smallest, these are Espiritu Santo, Malakula, Efate, Erromango, Ambrym, Tanna, Pentecost, Epi, Ambae or Aoba, Vanua Lava, Gaua, Maewo, Malo, and Anatom or Aneityum. The nation's largest towns are the capital Port Vila, situated on Efate, and Luganville on Espiritu Santo. The highest point in Vanuatu is Mount Tabwemasana, at 1,879 metres (6,165 ft), on the island of Espiritu Santo.
Vanuatu's total area is (roughly 12,274 square kilometres (4,739 sq mi)) of which its land base is very limited (roughly 4,700 square kilometres (1,800 sq mi)); most of the islands are steep, with unstable soils, and little permanent freshwater. One estimate (2005) is only 9% of land is used for agriculture (7% permanent crops, 2% arable land). The shoreline is usually rocky with fringing reefs and no continental shelf, dropping rapidly into the ocean depths.
There are several active volcanoes in Vanuatu, including Lopevi, as well as several underwater ones. Volcanic activity is common with an ever-present danger of a major eruption; a recent nearby undersea eruption of 6.4 magnitude occurred in November 2008 with no casualties, and an eruption occurred in 1945. Vanuatu is recognised as a distinct terrestrial ecoregion, known as the Vanuatu rain forests. It is part of the Australasia ecozone, which includes New Caledonia, the Solomon Islands, Australia, New Guinea, and New Zealand.
Vanuatu’s growing population (estimated in 2008 at 2.4 percent annually) is placing increased pressure on local resources for agriculture, grazing, hunting, and fishing. Some 90 percent of Ni-Vanuatu households fish and consume fish, which has caused intense fishing pressure near villages and the depletion of near-shore fish species. While well vegetated, most islands also show signs of deforestation. They have been logged (particularly of higher-value timber), subjected to wide-scale slash-and-burn agriculture, converted to coconut plantations and cattle ranches, and show evidence of increased soil erosion and landslides.
Freshwater is becoming increasingly scarce and many upland watersheds are being deforested and degraded. Proper waste disposal and water and air pollution are also increasingly troublesome issues around urban areas and large villages. Additionally, the lack of employment opportunities in industry and urban areas and inaccessibility to markets have combined to lock rural families into a subsistence or self-reliance mode, putting tremendous pressure on local ecosystems.