Santiago is the capital island and the largest (991 km2) in the archipelago of Cape Verde. It is distinguished by a broad network of ravines and valleys, whose source lies in the two massifs or mountain chains of Serra do Pico da Antónia (1064 m) and Serra da Malagueta (1392 m), the highest point. The magnificent cliffs of Baia do Inferno are located in the western sector and tower to over 400 m in some sections. The east coast, however, is generally low-lying, with intertidal zones and pebbly beaches of black sand; beaches of golden sands are few and far between.
A striking aspect of the geomorphology of Santiago is the absence of recent lava flows, while well-defined volcanic cones are infrequent. Erosion has evidently played a major role in recent millennia, in comparison with important volcanic action on other islands, Fogo in particular. Several valleys (especially on the southern flank) are heavily gravelled and U-shaped, which clearly points to the much greater age of these ravines, compared with others that are V-shaped. Rainfall is irregular, although it has been plentiful in recent years and the island landscape had been clothed in green from August-September to November, with the arrival of the monsoons. The highest annual averages are recorded in Serra da Malagueta, where they can exceed 650 mm. Logically, the highest temperatures are reached in low-lying areas, particularly in the south of the island.
With a population of 273 919 (2010 census), Santiago has come under considerably more African influence than the other islands. This is evidenced in the features of the local people and certain cultural manifestations that have crossed the centuries, such as the Tabanca ritual. From a historical perspective, it is worth mentioning that the capital of the archipelago was initially Ribeira Grande, subsequently named Cidade Velha, and situated to the west of Praia. This town was destroyed by French pirates, under the command of Jacques Cassard, in 1712, which led to capital status being transferred to Praia. Recently, Ribeira Grande was at the centre of an important restoration project, largely financed by the Spanish Agency for International Cooperation, which aided its declaration as a World Heritage Site by UNESCO.
Agriculture is still very important on Santiago, particularly where maize and feijões or kidney beans are concerned, as they provide a vital source of food for the local people. Tropical agriculture (mangos, bananas, coconuts, sugar cane and manioc) requires valleys with water resources and is practised in Ribeira Grande, Ribeira da Prata, Tarrafal, São Domingos, São Jorge dos Orgãos and Pedra Badejo. Sugar cane is also used to obtain grogue or aguardiente, a very strong alcoholic beverage, which is a kind of rum and is found throughout the islands. Stockbreeding is also a mainstay and encompasses cattle and goats, as well as donkeys. Fishing currently has its base in the port of Praia, as well as Tarrafal, Ribeira da Barca, Calheta de São Miguel, Pedra Badejo and Porto Mosquito. This activity has yet to be developed, but it has great potential as an important source of income for the country.
Population density is very high on Santiago and continues to grow with the arrival of inhabitants from other islands and the African continent. Although Praia is still the economic centre, in recent decades other towns are gaining in importance, including São Domingos, Assomada, Santa Cruz and Tarrafal. Tarrafal is currently the main tourist resort on the island, but there are also facilities at Baía de São Francisco. However, the area between Praia and Cidade Velha is destined for tourism development, golf course included. Finally, despite being only newly created, the public university, Universidade de Cabo Verde, is already carrying out important educational and scientific work, as well as building strong relations with other universities within Macaronesia, Europe and America.