landslides in any given location. Using GIS, extremely detailed maps can be generated to show past events and likely future events which have the potential to save lives, property, and money. Since the ‘90s, GIS have been also successfully used in conjunction to decision support systems, to show on a map real-time risk evaluations based on monitoring data gathered in the area of the Val Pola disaster (Italy). Prehistoric landslides Storegga Slide, some 8,000 years ago off the western coast of Norway. Caused massive tsunamis in Doggerland and other areas connected to the North Sea. A total volume of debris was involved; comparable to a thick area the size of Iceland. The landslide is thought to be among the largest in history. Landslide which moved Heart Mountain to its current location, the largest continental landslide discovered so far. In the 48 million years since the slide occurred, erosion has removed most of the portion of the slide. Flims Rockslide, ca. , Switzerland, some 10,000 years ago in post-glacial Pleistocene/Holocene, the largest so far described in the alps and on dry land that can be easily identified in a modestly eroded state. The landslide around 200 BC which formed Lake Waikaremoana on the North Island of New Zealand, where a large block of the Ngamoko Range slid and dammed a gorge of Waikaretaheke River, forming a natural reservoir up to deep. Cheekye Fan, British Columbia, Canada, ca. , Late Pleistocene in age. The Manang-Braga rock avalanche/debris flow may have formed Marsyangdi Valley in the Annapurna Region, Nepal, during an interstadial period belonging to the last glacial period. Over 15 km3 of material are estimated to have been moved in the single event, making it one of the largest continental landslides. Tsergo Ri landslide, a massive slope failure 60 km north of Kathmandu, Nepal, involving an estimated 10–15 km3. Prior to this landslide the mountain may have been the world's 15th mountain above 8000m. Historical landslides The 1806 Goldau landslide on September 2, 1806 The Cap Diamant Québec rockslide on September 19, 1889 Frank Slide, Turtle Mountain, Alberta, Canada, on 29 April 1903 Khait landslide, Khait, Tajikistan, Soviet Union, on July 10, 1949 A magnitude 7.5 earthquake in Yellowstone Park (August 17, 1959) caused a landslide that blocked the Madison River, and created Quake Lake. Monte Toc landslide () falling into the Vajont Dam basin in Italy, causing a megatsunami and about