The quest for immortality has captivated and confounded people for thousands of years, from the healing powers of the Holy Grail used by Jesus at the Last Supper, to the elusive Fountain of Youth and the storied philosopher's stone.

Relics from the crucifixion of Jesus Christ have fascinated the faithful for 2000 years, from the wooden cross and iron nails to the crown of thorns and Spear of Destiny. Experts examine whether these sacred artefacts still exist and where they are.

For millennia, there has been speculation about how the world will end, from the detailed account in the Book of Revelation, to the prophecies foretold by Nostradamus; a look into if whether or not any of these predictions could come true.

The legendary treasures of the Copper Scroll, King Solomon's mines, and the Syamantaka Gem have captivated the world for centuries. But could these vast fortunes still be out there, waiting to be discovered?

Most of the world's holiest places sit in plain sight, able to be seen and experienced, but there are some hidden deep underground.