The Archipelago of the Azores is composed of nine volcanic islands situated in the middle of the North Atlantic Ocean, and is located about 1,500 km (930 mi) west from Lisbon and about 3,900 km (2,400 mi) east from the east coast of North America. The islands, and their economic exclusion zone, form the Autonomous Region of the Azores, one of the two autonomous regions of Portugal.
There are nine major Azorean islands and an islet cluster, in three main groups. These are Flores and Corvo, to the west; Graciosa, Terceira, S A small number of alleged Hypogea, earthen structures carved into rocks that were used for burials, have been identified on the islands of Corvo, Santa Maria and Terceira by Portuguese archaeologist Nuno Ribeiro and speculations were published that they might date back 2000 years, alluding to a human presence on the island before the Portuguese.
However, these kind of structures have always been used in the Azores to store cereals and suggestions by Ribeiro that they might be burial sites are unconfirmed. Detailed examination and dating to authenticate the validity of these speculations is lacking. So far, it is unclear whether these structures are natural or man-made and if they predate the 15th century Portuguese colonization of the Azores. Solid confirmation of a pre-Portuguese human presence in the archipelago has not yet been published.