The observatory is a demi-plane within the Near Space. Who built it or why is unknown. The observatory is a colossal mechanism which houses innumerable portals to other realms and to other times.
The plane is nearly always devoid of life. The only creatures that regularly appear are the custodians, large, human-like constructs which occasionally appear, adjust some feature of the plane or remove debris and disappear again. Their true purpose and nature are unknown. They appear as featureless humanoid manikin constructs composed of brass and wax.
The inhabitants are easily dispatched and never turn hostile. If slain, another one will quickly appear and remove the remains.
The Eye is a large lens through which an operator can view any point in time on any plane, granted they are not somehow protected from simple scrying.
These shimmering gateways offer one-way travel to a point in time on a plane selected by the operator.