Kolat Towers

The building known as Kolat Towers started out as an old stone manor and a pair of sturdy cottages owned by the Watchful Order of Magists & Protectors. The wizard brothers, Alcedor and Duhlark Kolat, bought the buildings and, much to the chagrin of the local building guilds, stitched the building together using spells such as wall of stone and stone shape. The guilds of Waterdeep petitioned to have the building condemned, but were unsuccessful. A few locals applauded the brothers' thrift.
The brothers collected many magical artefacts, and experimented to create their own for sale in the city, but a rift grew between them, they each lived in a separate tower. After a break-in resulted in much of their collection being stolen, Duhlark became obsessively paranoid, and shielded the entire property within a thin wall of force. Alcedor believed his brother was secretely involved with the theft, and left Waterdeep entirely. Duhlark would die in the towers, and it's his ghost which is believed to be it's sole remaining inhabitant. For the last thirty years the towers have remained untouched, legally speaking still being Alcedor's property.
They were discovered by Polly Perrenporth and Eclipse of the Moon to potentially hold one of the Eyes of Golorr.

Blueprints of the original structure dated 1368, under ownership of the Watchful Order of Magists & Protectors before it's sale to the Kolat brothers.