The imperial tombs of Iran are astonishingly built on cliffs, but why?

The emperors of the Persian Empire are actually buried on the cliffs and bluffs, and it is particularly spectacular to visit them in the glow of the setting sun. It's truly an eye-opening experience! ⛰️ The Naqsh-e Rostam site, also known as the Persian imperial tombs, is located on a mountain cliff northeast of Shiraz near Persepolis in Iran, with four cross-shaped imperial tombs lined up in a row. 🤴 From left to right, they are the tombs of Xerxes the Great (reigned 486–464 BCE), Darius I the Great (reigned 522–486 BCE), Artaxerxes I (reigned 464–424 BCE), and Darius II (reigned 424–404 BCE). 🔥 Among them, Darius II led a Persian army of 100,000 to plunder the temples of the city of Athens and set fire to the entire Acropolis. Why were these emperors buried on cliffs? The ancient Persians believed that the world was composed of four elements: fire, water, earth, and wind, which could not be contaminated. Therefore, after death, bodies could not be buried underground as it would pollute the land, so they were buried on cliffs instead. 📌 The site is located 12 kilometers northwest of Persepolis in Iran. 💸 The entrance fee is 80,000 rials.