The Azores ( , ; ), officially the Autonomous Region of the Azores (), is one of the two autonomous regions of Portugal (along with Madeira). It is an archipelago composed of nine volcanic islands in the Macaronesia region of the North Atlantic Ocean, about west of Lisbon, about northwest of Morocco, and about southeast of Newfoundland, Canada. Its main industries are agriculture, dairy farming, livestock, fishing, and tourism, which has become a major service activity in the region. The government of the Azores employs a large percentage of the population directly or indirectly in the service and tertiary sectors. The largest city of the Azores is Ponta Delgada. The culture, dialect, cuisine, and traditions of the Azorean islands vary considerably, because these remote islands were settled sporadically over a span of two centuries. There are nine major Azorean islands and an islet cluster, in three main groups. These are Flores and Corvo, to the west; Graciosa, Terceira, São Jorge, Pico, and Faial in the centre; and São Miguel, Santa Maria, and the Formigas islets to the east. They extend for more than and lie in a northwest–southeast direction. All of the islands have volcanic origins, although some, such as Santa Maria, have had no recorded activity in the time since the islands were settled several centuries ago. Mount Pico, on the island of Pico, is the highest point in Portugal, at . If measured from their base at the bottom of the ocean to their peaks, which thrust high above the surface of the Atlantic, the Azores are among the tallest mountains on the planet. The climate of the Azores is very mild for such a northerly location, being influenced by its distance from the continents and by the passing Gulf Stream. Because of the marine influence, temperatures remain mild year-round. Daytime temperatures normally fluctuate between depending on season. Temperatures above or below are unknown in the major population centres. It is also generally wet and cloudy. History A small number of alleged hypogea (underground structures carved into rocks) have been identified on the islands of Corvo, Santa Maria, and Terceira by Portuguese archaeologist Nuno Ribeiro, who speculated that they might date back 2,000 years, implying a human presence on the island before the Portuguese. These structures have been used by settlers in the Azores to store grain and the suggestion by Ribeiro that they might be burial sites