Piton de la Fournaise, a typical basaltic shield volcano, located on the French island La Réunion, is one of the world's most active and productive volcanoes. It is in a phase of frequent but short-lived eruptions that start with lava fountains and produce large lava flows. Since the active areas of the volcano are not inhabited, its eruptions pose little danger and cause little damage.

Piton de la Fournaise is a typical example of a hot-spot volcano. The volcano is about 530,000 years old and during much of this time, its activity overlapped with eruptions of its older neighbor, the deeply dissected Piton des Neiges shield volcano to the NW.

Three calderas formed at about 250,000, 65,000, and less than 5000 years ago by progressive eastward slumping of the volcano. Numerous pyroclastic cones dot the floor of the calderas and their outer flanks. Most historical eruptions have originated from the summit and flanks of Dolomieu, a 400-m-high lava shield that has grown within the youngest caldera called the Enclos, which is 8 km wide and breached to below sea level on the eastern side. More than 150 eruptions, most of which have produced fluid basaltic lava flows, have occurred since the 17th century. Only six eruptions, in 1708, 1774, 1776, 1800, 1977, and 1986, have originated from fissures on the outer flanks of the caldera. The Piton de la Fournaise Volcano Observatory, one of several operated by the Institut de Physique du Globe de Paris, monitors this very active volcano.