About 30 kilometres east of Kermanshah on the Tehran highway, the Bisotun complex is one of the most extraordinary historical sites in Iran. High on a sheer cliff face, the Persian emperor Darius I (the Great) had a massive relief and trilingual inscription carved around 520 BC to record his accession to power and military victories. The text, in Old Persian, Elamite, and Babylonian cuneiform, was the key that unlocked the reading of these ancient scripts in the 19th century, making Bisotun as significant to the study of ancient languages as the Rosetta Stone.
Below the main inscription is a carved figure of Hercules reclining — a Hellenistic-era addition from the 2nd century BC. Other features of the site include Median-period bas reliefs, an Achaemenid caravanserai, and a series of caves showing evidence of human occupation from the Stone Age onwards. The site is a UNESCO World Heritage Site. You need binoculars to see the main inscription clearly from the ground; a guided visit helps decipher what you are looking at.