In the French Alps, the Serre-Ponçon lake, the largest artificial reservoir in the region, covers an area of 2,800 hectares. This vast body of water was created by the construction of a massive dam, which required the relocation of approximately 2,000 people. The dam was built to control the Durance River, which historically caused devastating floods, and to generate hydroelectric power for post-war France. The site of the lake was once home to two villages—Savines and Ubaye—that were completely razed before the reservoir was filled in 1961. Today, only fragments of their past remain, such as foundations, an old bridge, and scattered stones, which occasionally resurface during severe droughts when the water level drops significantly. The idea of building a dam on the Durance dates back to the 1850s, following major floods that devastated the region. However, the challenging geology of the area—including unstable soil, seismic activity, and geothermal heat—made the initial construction plans unfeasible. The original plan for a 50-meter-high dam was deemed too modest, and it wasn't until the mid-20th century that technology advanced enough to realize the more ambitious vision. In 1955, the French electricity company EDF was commissioned to build the dam, which stands 124 meters high and spans 650 meters in length. The construction involved over 3,000 workers and required more than 14 million cubic meters of earth and rock. Engineers borrowed techniques from American earth dams to adapt to the valley’s unique conditions. Before the dam was completed, the valley was completely emptied of its residents. Villagers were relocated, their homes demolished, and cemeteries moved. The last structure to be removed was the church of Vieux Savines on May 3, 1961, just before the reservoir was filled. The human impact was significant: nearly 2,000 people were displaced, and three villages—Savines, Ubaye, and Rousset—were submerged. While some sources estimate the number of displaced families to be around several dozen, the exact number remains uncertain. The filling of the reservoir took nearly two years, from November 1959 to May 1961, and the villagers had no say in the process. Some still remember the project with bitterness, as it disrupted their traditional way of life as shepherds, blacksmiths, and herders. Today, the Serre-Ponçon lake continues to serve its original purpose: controlling floods and generating electricity. It also provides essential water for irrigation in Provence and drinking water for the region. The dam’s power plant produces 700 million kWh of electricity annually, supplying clean energy to the South Provence-Alpes-Côte d'Azur area. While the lake has grown to cover dozens of kilometers of shoreline, the memory of the vanished valley still lingers. Occasionally, during severe droughts, remnants of the old village—like the 12th-century chapel of Saint-Michel—emerge above the water, serving as a reminder of the past. However, no entire homes resurface, as all structures were demolished before the reservoir was filled. The lake remains a vast, turquoise expanse, welcoming thousands of visitors each summer, while the echoes of the submerged valley rise, stone by stone, whenever the water level drops.