Underwater monolith 60 Km offshore from Sicily
Links:
https://en.wikipedia.org/wiki/Pantelleria_Vecchia_Bank_Megalith
https://www.dailymail.co.uk/sciencetech/article-3192145/Underwater-Stonehenge-style-rock-Mediterranean-Sea-Monolith-served-lighthouse-10-000-years-ago.html
https://www.archaeology.org/news/3548-150807-underwater-mesolithic-monolith
https://www.sciencedirect.com/science/article/abs/pii/S2352409X15300535?via%3Dihub