In a groundbreaking discovery, archaeologists have uncovered a submerged man-made bridge in a cave on the Spanish island of Mallorca, suggesting that human settlement on the islands may have occurred earlier than previously thought.
The 7.6-meter-long bridge was found inside Genovesa Cave, where distinct calcium deposits had formed along its surface during periods of high sea levels. The study, which relied on dating phreatic overgrowth on speleothems (mineral deposits), provided a time frame for human activity on the bridge.
The bridge, displaying a distinctive coloration band near its top, lies at a depth of 1.1 meters—precisely the same depth as the dated mineral deposits, indicating a period of sea-level stability between 6,000 and 5,400 years ago.
“The presence of this submerged bridge and other artifacts indicates a sophisticated level of activity, implying that early settlers recognized the cave’s water resources and strategically built infrastructure to navigate it,” study co-author Bogdan Onac said.
Constructed from large limestone blocks, some as wide as 1.3 meters, the bridge’s exact construction method remains unknown. This discovery, along with evidence of other ancient environmental events on the island, such as the extinction of the goat-antelope Myotragus balearicus, coincides with the revised timeline of human settlement on Mallorca.
This finding challenges the long-held belief that human settlement on the island began around 4,400 years ago.
Onac highlighted the importance of interdisciplinary collaboration in uncovering historical truths and advancing the understanding of human history.
Scientists plan to continue exploring cave systems in the Mediterranean, hoping to access ancient caves to study the impact of modern climate change on sea-level rise.