BWB – Volcanic Pools and Their Formation

Volcanic pools are among the most well-known natural formations on Madeira and other volcanic islands in the Atlantic Ocean. They are created through the interaction of lava, ocean water, and erosion over very long periods of time. Unlike artificial swimming pools, these pools are natural structures directly connected to the volcanic origin of the island. Along Madeira’s coastline in particular, large areas of lava rock can still be found, formed by volcanic eruptions in the distant past.

Millions of years ago, hot lava flowed from volcanoes into the Atlantic Ocean. When the molten rock came into contact with the cold seawater, it cooled rapidly and solidified. Over time, irregular rock formations developed along the coastline. Some of these lava formations created natural depressions or protected basins between the rocks. Through the constant movement of the Atlantic waves, these areas gradually filled with seawater, forming natural ocean pools.

The power of the ocean continues to play an important role in shaping them today. Waves, currents, and erosion constantly alter the rocks, although usually very slowly. During rough seas especially, the water strikes the lava coastline with enormous force. Small pieces of rock are gradually worn away, while existing formations continue to be shaped over time. At the same time, volcanic rock often remains stable for very long periods due to its hardness.

Many volcanic pools are surrounded by dark basalt rock, which is typical of volcanic islands such as Madeira. The natural shapes of the lava stones give the pools their irregular and untouched appearance. Depending on tides and wave conditions, the water exchange within the pools also changes continuously. Fresh seawater is therefore constantly flowing into them.

Some of Madeira’s best-known volcanic pools are located in Porto Moniz on the island’s northern coast. There, natural lava basins formed over time and have since been partially adapted to allow visitor access. Despite minor modifications, their geological foundation remains entirely natural. The pools directly connect Madeira’s volcanic history with the power of the Atlantic Ocean.

Volcanic pools clearly demonstrate how landscapes are formed and shaped through natural processes over long periods of time. They are the result of former volcanic activity combined with the constant movement of the ocean. Today, they are among Madeira’s most impressive coastal landscapes and highlight the close relationship between volcanism and the Atlantic Ocean.

© Photo by Associação de Promoção da Madeira

By Fatima Kutzschbach