The creation of the Lake Omodeo reservoir in the 20th century flooded agricultural valleys and small villages in central Sardinia, reshaping the surrounding region. However, the valley’s history did not vanish completely beneath the water. During severe summer droughts when water levels drop significantly, ancient stone structures, abandoned bridges, and even prehistoric Nuragic sites re-emerge from the lake. This temporary re-emergence offers a tangible reminder of how modern engineering altered Sardinia’s inland geography.