Alfava Metraxis
Alfava Metraxis[source needed] was a planet home to the Aplan, but in the far future was terraformed and colonised by Human settlers.
The Aplan left notable landmarks on the planet, including the Aplan Mortuaria, sometimes known as Mazes of the Dead. These were large subterranean labyrinths with tombs in the walls, adorned with statues of the dead. The Mazes have six levels, to represent the ascent of the soul.
The civilisation of the Aplan was noted to have mysteriously come to an abrupt end. This was revealed to have been caused by the Weeping Angels, which infested the dark underground Mazes, well hidden amid the numerous statues. Having hunted the Aplan to extinction, the Angel colony lacked any further energy source, and hence fell into slow decay. By the time human settlers reached the planet, the angels within the mazes were too weak to venture out to attack.
By the 51st century, a lone, healthy Angel feigned dormancy and allowed itself to be captured to ensure that it was placed on a ship with a temporal core and when close to the planet crashed it on top of the temple. It used its powers to make sure the core didn't explode and directed the energy so it could recharge its brethren.
When the Byzantium crash landed there the Doctor, Amy Pond and River Song went to the temple there to investigate and save the people on the Byzantium. (DW: The Time of Angels)
