A submerged, human-constructed limestone bridge found inside a cave on a Spanish island is much older than previously thought, pushing back the record of when humans inhabited the location, a new study finds.
Researchers discovered the limestone bridge in 2000 during a scuba-diving expedition inside the flooded cave in Mallorca, a Mediterranean island located off the eastern shore of Spain's mainland. At the time, researchers determined that the 25-foot-long (7.6 meters) bridge, which consists of large limestone blocks stacked on top of each other, was built around 4,400 years ago, according to a study published Friday (Aug. 30) in the journal Communications Earth & Environment.
