In the modern, ‘free world’, one would think that a passport and valid visa entitle you to visit any place on earth you want to explore, but there are still some spots that are out of bounds for ordinary mortals.

1. Area 51, Nevada. Shrouded in secrecy and breeding ground for multiple conspiracy theories, Area 51 is a place you can’t ever see, even on an aerial-view map. It’s a remote wing of the Edwards Air Force Base in the U.S, believed to be a testing facility for top-secret aircraft and weaponry being developed by the American government. The rumors that it’s home to a crashed alien spacecraft and remains of dead alien cosmonauts keeps curious tourists flocking to the place, but no one can enter the actual facility without military clearance.

2. Vatican Secret Archives, Italy. Located under Vatican City, these vaults contain thousands of historical records, state documents, papal archives and letters from famous historical personalities like Mary Queen of Scots and Michelangelo. There’s also a letter from England’s King Henry VIII, requesting an annulment of his marriage to his first wife, Katherine of Aragon. The request was refused, of course, resulting in England’s divorce from the Catholic Church. Only a few select scholars are ever allowed in here, after gaining special permission from the Pope.

3. Lascaux Caves, France. Since the year 2008, entry into these historical caves is forbidden, for fear of damage to the nearly 17,000 year-old Paleolithic wall paintings they contain. They are now a protected UNESCO World Heritage Site.

4. Svalbard Global Seed Vault, Norway.  An 11,000 sq foot facility on the island of Spitsbergen, the subterranean vault stores 840,000 samples of seeds, kept in reserve by governments or institutions. They are to be used in case of any regional or global catastrophe causing food shortage. Highly advanced security systems protect the facility, which is inaccessible to ordinary people.

5. Tomb of Qin Shi Huang, China. The last resting place of China’s first emperor has been preserved since 210 BC. It’s a network of caves containing artifacts like the famous Terracotta Army, clay replicas of soldiers that were believed to protect the ruler in the after-life. The Chinese government has banned entry into the caves for preservation purposes.