From the World Heritage inscription:
Dominating the mountainous landscape of St Lucia are the Pitons, two steep-sided volcanic spires rising side by side from the sea. Gros Piton (770 m) is 3 km in diameter at its base, and Petit Piton (743 m) is 1 km in diameter and linked to the former by the Piton Mitan ridge.
The Pitons are part of a volcanic complex, known to geologists as the Soufriere Volcanic Centre which is the remnant of one (or more) huge collapsed stratovolcano. The volcanic complex overlies a tectonic plate subduction (underthrusting) zone which stretches 700 km along Lesser Antilles, forming a volcanic arc.
The Pitons are the eroded cores of two lava domes formed on the flanks of the stratovolcano. Today they tower above a caldera-like formation, produced by a gigantic gravity slide or structural collapse which formed the Qualibou Depression, 7 km in diameter. Near the centre of the depression are the Sulphur Springs, an active, high temperature geothermal field with sulphurous fumaroles and hot springs. The Pitons occur with a variety of other volcanic features including cumulo-domes, explosion craters, pyroclastic deposits (pumice and ash) and lava flows. Collectively, these fully illustrate the volcanic history of an andesitic composite volcano associated with crustal plate subduction.
The Marine Management Area is a coastal strip 11 km long and about 1 km wide. It comprises a steeply sloping continental shelf with fringing and patch reefs, boulders and sandy plains. The coral reefs, which cover almost 60% of the marine area, are healthy and diverse. A survey to a depth of 20 m revealed 168 species of finfish, 60 species of cnidaria, including corals, molluscs, sponges, echinoderms, arthropods and annelid worms. Hawksbill turtles are seen inshore, and whale sharks and pilot whales offshore.
The Pitons might very well be the most awe inspiring view in the entire Caribbean. The peaks are so important to the identity of St. Lucia that they appear on the national flag, the most popular beer in the country is named after it, and it appears on almost every souvenir you can buy on the island.
It is situated above the town of Soufrière in the south-west corner of the island. It is probably the most popular attraction on the island and there are many day tours which visit the area. It is also a popular destination for people visiting for the day on a cruise.