The study of landslides concerns stability conditions of subaerial and submarine slopes accounting for morphological, geological, geotechnical and geophysical properties of soils with development of numerical models aiming at determining the incipient failure and involved volumes. The study covers also the simulation of landslide evolution to compute trajectories, acceleration and velocity of the sliding body, to estimate the zone where it stops and deposit forms, and the impact on the environment. Furthermore, when slope failures occur close to water basins or underwater, models compute the impact on the water body (see the case of the 1963 Vajont landslide) and the generation of tsunamis (see the 2002 Stromboli tsunami).