This group of islands in mid-Atlantic is located 1500 kilometres to the west of the Portuguese mainland. Iit was known in ancient times, and was rediscovered by the Portuguese, who still control the islands, in 1432. The group consists of nine volcanic islands, with a total area of 2.300 km². The main island is São Miguel with the capital city of Ponta Delgada, the others are Corvo, Faial, Flores, Graciosa, Pico, Santa Maria, São Jorge and Terceira. The climate is maritime sub-tropical, the air is almost always warm and humid, with humidity levels of 75 to 90 per cent. The Portuguese brought vines from their home country, the first motivation for planting vines was to be able to produce wine for communion. By the 17th century, vines were grown on all the islands, and wine was even being delivered to the court of the Russian czar. Many vineyards were destroyed by mildew and phylloxera in the 19th century. There are areas defined as IPR on three of the islands, these are Biscoitos (this tiny island is considered to be part of Terceira), Graciosa and Pico. The main focus is on white wines with a high level of acidity, made from Arinto, Fernao Pires, Terrantez and Verdelho, these are also fortified. Vinho do Cheiro (smelling wine) is made from American varieties, and is produced on all the islands. Graciosa is also known for Aguardente (brandy). A special feature on Pico are the vineyards enclosed by walls of volcanic rock that protect the vines from the strong ocean winds.