Emily Chan
On a Spanish island, a human-made bridge submerged underwater was discovered inside a cave during a scuba expedition in 2000.
A new study has found that the limestone bridge is much older than previously thought, which means that humans have occupied the area for far longer than assumed.
The bridge was located in Genovesa Cave in Mallorca, a Mediterranean island off the eastern shore of Spain’s mainland. It was 25 feet in length and was made of large, heavy blocks of limestone stacked on top of each other.
Some of the blocks measured 4.2 feet across. Initially, researchers determined that the bridge was built around 4,400 years ago.
“This dating was based on pottery fragments that were found inside the cave,” said Bogdan Onac, the lead author of the study and a professor of geology at the University of South Florida. “But now, we know that this [date] was wrong.”
Among the broken pottery pieces, there were also bones littered on the floor of the flooded cave. The bones belonged to a now-extinct goat-antelope creature called Myotragus balearicus.
Mallorca is a large island, but it was one of the last to be settled in the Mediterranean. The earliest islands in the area, Cyprus and Crete, were occupied at least 9,000 years ago.
A lack of historical records and limited archaeological evidence have made it challenging to pinpoint when humans colonized and settled on the Mediterranean islands.
To figure out exactly when the bridge was constructed, the study authors examined a “distinct light-colored band” that resembled a bath ring. It ran along the upper portion of the bridge. The shift in coloration indicated changes in sea levels. When the water rose, calcite encrustations formed on the bridge.
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