Temple of Atropos

 was a temple on the planet Time. It contained the Mouri as well as the Priest Triangles. (TV: War of the Sontarans)

The Dark Times
In the Dark Times, the Fugitive Doctor was sent on a mission by the Time Lords to enter the Temple as part of the Seige of Atropos, which had been captured by Old Swarm and Azure, and reinstate the Mouri. Her, Karvanista, and two other Gallifreyans achieved this by hiding the Mouri inside a Passenger, tricking Swarm and Azure into releasing them back to where they belonged.

The Thirteenth Doctor, whilst inside her time stream, witnessed the Seige of Atropos, with herself, Dan, Yaz, and Vinder taking the places of the Fugitive Doctor and her companions. (TV: Once, Upon Time)