Known as "The Eye" or El Ojo, this mysterious 387-foot-wide, perfectly circular floating island in Argentina's Parana Delta moves freely across a crystal-clear lake, baffling experts. Its smooth circular shape is believed to be the result of erosion caused by water currents, which also drive its rotation. Famed Argentinian filmmaker Sergio Neuspiller, who visited the island, was struck by its beauty and the transparent yet dark-looking cold water beneath it, a rarity in the region. While scientists attribute the phenomenon to natural processes, theories ranging from ancient civilizations to extraterrestrial activity, including claims of a hidden UFO base, have sparked intrigue.
Image credit: Argentina Government (CC BY 4.0)