In May 1706, after several earthquakes, an eruptive fissure opened in the hills of the Garachico district, forming the Montaña Negra Volcano. In < 15 h the village of El Tanque and part of the town of Garachico, including the harbour, were buried under lava flows. A week later, another flow buried the village of San Juan del Reparo and much of the remaining town of Garachico. Today, over 6700 people live in the immediate vicinity of this former eruption. Although most of the population is concentrated in the main villages, dwellings are located throughout the district and any future eruption will inevitably destroy property. The reconstruction of the 1706 eruption shows that in any future event only a short time will be available to evacuate the population, but it may be possible to try to prevent the effects of the flows.