Despite the rapid growth of global travel and technology, there are still places on Earth shrouded in secrecy, danger, or deep cultural respect-completely off-limits to the public. These 13 forbidden places are so mysterious, they only fuel human curiosity even more.

From the Lascaux Caves in France, closed to preserve ancient 17,000-year-old art, to the Snake Island in Brazil, swarming with thousands of deadly golden lancehead snakes-each location is a story in itself. North Sentinel Island in India is fiercely protected by an isolated tribe, while Area 51 in the USA remains a conspiracy theorist’s dream. Surtsey Island (Iceland) and Heard Island (Australia) are no-go zones due to ecological preservation.

You can’t visit the Doomsday Vault in Norway, the sacred Ise Grand Shrine in Japan, or Niihau Island in Hawaii unless you belong to the royal family or U.S. Navy. These places challenge our urge to explore the unknown-reminding us that mystery still exists in a well-connected world.