Here, in Naqsh-e Rustam, the rock itself parts to reveal a doorway to the past, where one of history's most powerful rulers sleeps in his vertical palace. Once a king who commanded armies that shook the earth, now Xerxes keeps silent watch over the lands he once ruled, his tomb a testament to immortal ambition. But even in death, mystery shrouds the Great King - assassinated by his own guard, his final moments as dramatic as his legendary life.

Some say the mountain doesn't hold a tomb, but rather a portal to ancient Persia's golden age.