Phimeanakas ("Heavenly Palace") is a small Hindu pyramid temple inside the walled compound of the Angkor Thom Royal Palace. Built primarily in the late 10th and early 11th centuries, it predates the construction of Angkor Thom itself and was incorporated into the palace enclosure when Jayavarman VII rebuilt the capital. The pyramid has three tiers of sandstone and laterite, and the steep stairways on each of its four sides are still climbable.
The temple is less visited than other sites in Angkor Thom largely because its superstructure has almost completely disappeared, leaving a bare pyramid platform. But the Royal Palace compound that surrounds it — including the Terrace of the Elephants and the Terrace of the Leper King just to the north — is worth exploring. The Chinese envoy Zhou Daguan, who visited Angkor in 1296 and left the most detailed eyewitness account of the Khmer Empire in its final decades, wrote that the king was obliged to sleep each night in Phimeanakas, where a nine-headed serpent spirit would take the form of a woman and visit him — if the king failed to appear, disaster would follow. It is the kind of detail that makes the ruins feel inhabited again.