The Vajont Dam (or Vaiont Dam) is a disused dam, completed in 1959 in the valley of the Vajont River under Monte Toc, 100 km north of Venice, Italy. A 1963 landslide caused the overtopping of the dam and around 2,000 deaths.
One of the tallest dams in the World, it is 262 m (860 ft) high, 27 m (89 ft) thick at the base and 3.4 m (11 ft) at the top. Its 1963 over-topping was caused when the designers ignored the geological instability of Monte Toc on the southern side of the basin. Warning signs and negative appraisals during the early stages of filling were disregarded, and the attempt to complete the filling led to a landslide, which created a wave that brought massive flooding and destruction to the Piave valley below, wiping out several villages completely.