The island of Flores, with an area of 55 square miles (143.11 km2), is 11 miles (17 km) long and 7 miles (12.5 km) at its widest point. The highest part of the central plateau is Morro Alto with an altitude of 3,000 feet (914 m). The island is situated on 31º 59′ west longitude and 39º 25′ north latitude.
Flores developed initially from a submarine volcano from the Pleistocene period that constructed small calderas and numerous volcanic cones. Following a long period of quiescence beginning about 200,000 years ago, several young craters and associated lava flows erupted during the Holocene period including two about 3,000 years ago. The “Funda de Lajes” tuff ring formed about 3150 years ago was accompanied by a lava flow that traveled toward the southeast reach the area of Lajes.
The Island has deep valleys and high peaks. Morro Alto is the highest peak of the island reaching an altitude of 915 meters. It has several inactive volcanoes including “Caldeira Funda das Lajes” last erupted in 1200 BC, and “Caldeira Comprida” last erupted in 950 BC. Some of these volcanoes have calderas (“caldeiras” in Portuguese) in which water has collected to form lakes. There are seven of these lakes on the island. The caldera “Lagoa Funda” is considered the best. “Aguas Quentes” are small hot springs of boiling sulfurous water. “Gruta de Enxareus” is an enormous grotto, about 50 meters long and 25 meters wide.