Naqsh-e Rostam or Naqsh-e Rustam is an ancient burial site for Persian emperors located 12km northwest of Persepolis. There are four tombs carved in the cliffs in cross shapes, all lying about 10-20m above the ground. The tomba are said to be those of Darius II, Artaxerxes I, Darius I and Xerxes I. At the Naqsh-e Rostam site there are also some bas-reliefs carved in the rock representing war scenes and royal events. The Kaba-ye Zartosht tower is a cubical structure thought to be either a royal tomb, a calendar or a treasury.