Azores inhabitants. The nine islands that compose the archipelago occupy a surface area of , that includes both the main islands and many islets located in their vicinities. Each of the islands has its own distinct geomorphological characteristics that make them unique: Corvo (the smallest island) is a crater of a major Plinian eruption; Flores (its neighbor on the North American Plate) is a rugged island carved by many valleys and escarpments; Faial characterized for its shield volcano and caldera (Cabeço Gordo); Pico, is the highest point, at , in the Azores and continental Portugal; Graciosa is known for its active
Azores caldeira", the noted hot springs grotto. In 1869, the author Mark Twain published "The Innocents Abroad", a travel book, where he described his time in the Azores. The first reference to the island of São Jorge was made in 1439 but the actual date of discovery is unknown. In 1443 the island was already inhabited but active settlement only began with the arrival of the noble Flemish native "Wilhelm Van der Haegen". Arriving at Topo, where he lived and died, he became known as "Guilherme da Silveira" to the islanders. João Vaz Corte-Real received the captaincy of the island in