Mystery of the Tumuli

The Isle of Pines in New Caledonia is home to over 400 mysterious tumuli, or mounds, which have puzzled archaeologists. These mounds, averaging 2-3 meters in height, contain concrete and iron structures that seem to predate known human use of these materials. Excavations have revealed large concrete blocks with vertical shafts and iron cones beneath them, but their purpose remains unknown. Despite numerous theories, including ancient human construction and natural phenomena, no consensus has been reached on their origin or function, leaving the tumuli an enduring archaeological mystery[1][2][3][4].

Sources
[1] The Mystery of the Tumuli – Popular Archeology https://popular-archaeology.com/article/the-mystery-of-the-tumuli/
[2] The Isle of Pines Mounds: A South Pacific Mystery Solved? https://www.ancient-origins.net/unexplained-phenomena/isle-pines-0014166
[3] The mounds of the Isle of Pines : r/UnresolvedMysteries - Reddit https://www.reddit.com/r/UnresolvedMysteries/comments/ih7nj4/the_mounds_of_the_isle_of_pines/
[4] The Mysterious Tumuli Of New Caledonia - Science Frontiers https://www.science-frontiers.com/sf043/sf043p01.htm
[5] Isle of Pines (New Caledonia) - Wikipedia https://en.wikipedia.org/wiki/Isle_of_Pines_%28New_Caledonia%29
[6] The island's history - New Caledonia - Isle of Pines https://www.isle-of-pines.com/history.html
[7] Sample text for Library of Congress control number 2006007631 https://catdir.loc.gov/catdir/enhancements/fy0644/2006007631-s.html