Maio (269 km2) is relatively flat and similar to Sal and Boavista, where wide stony plains, dune fields and sandy beaches are the main features. The highest point is Monte Penoso, at 436 m altitude. Since Maio is one of the oldest islands in the archipelago and there have been no recent volcanic events, erosion has fashioned a stark landscape with very few high elevations. Apart from Monte Penoso, the only other high points are Monte Forte (312 m) and Monte Batalha (294 m). There are, however, several saline depressions near the shoreline (especially at Vila do Maio-Morro, in the south, and Terras Salgadas, in the north), which fill with tidal waters. As Maio is a low-lying island and relatively close to the African coast, temperatures are notably higher than on the more mountainous islands of the archipelago. It is also frequently beset by what is known locally as ‘dry mist’ or the dust-laden harmattan wind that blows across from the Sahara. Rainfall is low with an annual average of 370 mm.
The population of Maio is 7 000 inhabitants (2010 census). The economy has been traditionally based on salt collection, fishing, agriculture (currently minimal) and stockbreeding, particularly goats. The salt flats, located near Vila do Maio, the capital, were intensely exploited in the 19th century, but had already become important for the local economy in the previous century. The salt flats are located in a broad natural hollow, which is flooded by the tides. Other important activities in the past included the production of lime and clay, for making pottery. In more recent times, charcoal was also produced; Maio has the largest plantation of acacias in the archipelago and is often referred to as the ‘forestry reserve of Cape Verde’. In the last twenty years, the tourist trade has gradually increased, thanks to more infrastructure in Vila do Maio, Morro and Ponta Preta. However, the population of Maio barely grew from 2000-2010, in stark contrast with Boavista, whose population doubled. Tourism in Maio has not developed at the same pace as on Sal and Boavista.
Maio is named for the month of May 1460, when it was discovered by Diogo Gomes and Antonio da Noli, from Genoa, both in the service of the Portuguese Crown . One of the most dramatic aspects of its history was the series of food crises that plagued the archipelago, and this island in particular. The ensuing death toll moved most of the population to emigrate in search of a better life.