Geologically, the Pitons are volcanic plugs, cooled lava that blocks the vents of active volcanoes, and the area around them is rife with geothermal activity. Hot springs and fumaroles bring visitors to Sulphur Springs Park, which has been called the Caribbean's only “drive-in volcano.”

The Pitons—Gros Piton and Petit Piton—are technically classified as dormant volcanic plugs, not active volcanoes. They are massive spire-like landmarks formed by lava that hardened within the vent of an ancient volcano, which then eroded away over millions of years to leave the "plugs" standing. While they are part of the larger Soufrière Volcanic Centre (also known as the Qualibou caldera), which is considered an active volcanic area due to the presence of boiling sulfur springs and geothermal activity at the nearby "drive-in volcano," the Pitons themselves have not erupted for hundreds of thousands of years. They were designated as a UNESCO World Heritage site in 2004 and are safe for hiking, though the surrounding geothermal field is still monitored by scientists for signs of seismic or volcanic unrest.