Castle Ouroboros, also known as Malam’s Perch, is the Watchmen base of operations. The fortress is hidden within the Dimension of Time somewhere in orbit around Golarion. Rhodin first encountered Malam here when he was called as a Watchman, and Malam conducted the Watchmen’s affairs from this fortress.
Episode 71: The Call of Chevaghol – Chapter One
The Initiative traveled to Castle Ouroboros to confront Malam and obtain his blood, allowing them to return to the past using the Dragon Watch.