The Obelisk of Darkness, nestled amongst wreckage of a devastating impact in the Mhojave Desert, was an area sacred to Twilight, the Dark Father. Teneb, a lich who sustains life through the Divine Will of Twilight, resided here. A Chamber of Study offered books on topics related to Darkness.
The Obelisk was originally situated in Hashan before being ripped out and thrown into the Southern Sea near the Southern Vashnars by Neraeos, God of the Sea. The Temple of Fluvialis now resides in its place. As mentioned above, the Obelisk was relocated a third time to the Mhojave several decades later.
In response to the Darkwalkers using the power of the Darkenwood to cut Celestia off from the Prime Material Plane, effectively separating Priests from their angels, the Astraeans gathered outside the Obelisk of Darkness in 566 AF and raised an altar to their Goddess, Miramar. As the Scales of Justice descended from the Vault and fell into balance, the altar unleashed its power, obliterating the Obelisk.