This is the under dungeon located on the basement of an old abandoned mage tower in Netheril. The tower is now in de desert of Anauroch in one oasis

Beneath an abandoned Netherese mage tower, a cracked stairwell descends into an old maintenance entrance built from black stone and silver inlays. Flash floods from the oasis have invaded the lower halls, filling channels with shallow water and loosening the sand around ancient wards. A sealed bronze door marks the boundary between this neglected threshold and the deeper chambers where a magical catastrophe was contained.

Beneath an abandoned Netherese mage tower lies a buried complex of cisterns, spell-storage vaults, and apprentice workrooms. The upper galleries remain partially intact, but water from the oasis has invaded the dungeon and carried a corrupting influence upward from the depths. Explorers can follow the main route, investigate forgotten side chambers, or uncover a secret passage leading toward the deeper threat.

The Ashen Mnemonic is the lower vault beneath an abandoned Netherese mage tower, sealed beneath the sands of Anauroch and reached through the Servitor Galleries. Its compact chambers hold a damaged memory archive, stasis cells, and the remnants of a prison built to contain magical beings that outlived their creators. Deeper within, a broken spell-engine leaks toxic power into the surrounding desert and feeds the defenses of the final sanctum.

Beneath an abandoned Netherese mage tower lies a sealed system of prisons, archives, and arcane cooling chambers. The dungeon draws water from the oasis above, but centuries of magical contamination have awakened an intelligence buried within the tower's power core. Deeper passages distort distance, gravity, and memory as the failing system prepares to release its master.

A desert-adapted crystalline ankheg mutated by leaking Netherese magic, serving as a territorial patrol hazard near the Sandglass Vestibule.

Custodian Veyr is a Netherese maintenance construct corrupted by centuries of exposure to a damaged arcane core. It guards the Servitor Galleries by controlling doors, water channels, floor wards, and force barriers, while trying to contain both the first monster and any living creature it identifies as contamination.

The Mnemonic Wyrm is a failed Netherese attempt to preserve a dying archmage's consciousness by binding it to the Starless Prison's archive. The ritual succeeded only by merging the archmage with the memories of every captive stored in the vault. Now it is a starving, fragmented intelligence that feeds on recent thoughts while trying to remember who it was.