Lagoa do Fogo (Lake of Fire) is a crater lake within the Água de Pau Massif stratovolcano in the center of the island of São Miguel in the Portuguese archipelago of the Azores. The highest lake located on the island of São Miguel, the region is protected by governmental regulation that does not permit any constructions around the lake. History Since 1974, the Lagoa do Fogo had been under the administration of national legislation as a protected area, forming the Reserva da Lagoa do Fogo (Natural Reserve of Lagoa do Fogo) an area that includes approximately , founded by Decree-law 152/74 (15 April 1974). It was also covered under a supplementary Decree-Law 9/79. The Reserva Natural da Lagoa do Fogo was created in 1982, under terms of Regional Decree 10/82/A on 18 June 1982. Part of the area was included in the Natura 2000 network, and classified as the Site of Communitarian Importance of Lagoa do Fogo. The nature reserve was integrated into the Nature Park of São Miguel, under Decree-Law 19/2008A (8 July 2008), which included the entire watershed of the Laoga. Geography Lagoa do Fogo is one of the largest of the waterbodies in the Azores, and occupies the central caldera of the Água de Pau Massif, in the central area of the island of São Miguel. The caldera is the youngest volcano on the island of São Miguel, formed approximately 15 000 years ago, resulting from the collapse at the top of the volcano, some 5000 years ago. The last eruption occurred in 1563. It falls within the borders of the civil parishes of Conceição, Matriz and Água de Alto, in the municipalities of Ribeira Grande and Vila Franca do Campo, respectively. It is part of the hydrological watershed of the same name. The margins of the lake are located above sea level, although the crater rim, which extends to Pico da Barrosa is located at approximately altitude. The internal flanks of the crater (characterized by abrupt 48º cliffs) are occupied by the elliptical lake, and deep. The carved relief affects the course of hydrographic run-off, which is accentuated by torrential precipitation in the region, resulting in accentuated erosion and deposition along the margins. A majority of the watercourses are temporary or torrential, with the greatest run-off occurring in the winter, and little in the summer, with few permanent ravines. There are only two permanent effluents in