Area 51 is one of the most secretive places in the world. It is totally off-limits to the commoners, and even the USA barely acknowledges the existence of Area 51.
This island in Brazil is infested with thousands of deadly snakes. No human even dare to tread on Snake Island, and it is regarded as the most forbidden places in the world.
The Doomsday Vault is a seed bank situated in the heart of the Arctic Svalbard archipelago. It is an attempt to safeguard the seeds in case of an apocalypse or global crisis.
Lascaux Cave contains pre-historic paintings that are 17,300 years old. The cave is closed to the general public since 1963.
Room 39 is one of the most secret organizations in the world's most secretive state. No one actually knows what's inside this mysterious room.
People inhabiting the island resist contact with the outside world, so much so that, the Indian government had to ban visitors.
North Brother Island is one of the most popular abandoned places in the USA. It is permanently shut for the common people.