Four tombs belonging to Achaemenid kings are carved out of the rock face. They are all at a considerable height above the ground. The tombs are known locally as the 'Persian crosses', after the shape of the facades of the tombs. The entrance to each tomb is at the center of each cross, which opens onto to a small chamber, where the king lay in a sarcophagus. The horizontal beam of each of the tomb's facades is believed to be a replica of the entrance of the palace at Persepolis. One of the tombs is explicitly identified by an accompanying inscription to be the tomb of Darius I the Great (c. 522-486 BC). The other three tombs are believed to be those of Xerxes I (c. 486-465 BC), Artaxerxes I (c. 465-424 BC), and Darius II (c. 423-404 BC) respectively. A fifth unfinished one might be that of Artaxerxes III, who reigned at the longest two years, but is more likely that of Darius III (c. 336-330 BC), last of the Achaemenid dynasts.