Neuropolis is the name of the city once known as Tucson in the U.S. state of Arizona, which served as the home of the Rossum Corporation in its pre- and post thought-pocalypse state.
By 2020, Neruopolis had become a defended compound controlled by Matthew Harding and Clive Ambrose, the former of whom mainly used his power to indulge in physical appetites, moving to a new body when the one in use gets to out of shape, much to the disgust of Ambrose. Topher Brink had also been captured by this year, and held prisoner within the compound; while he was there, prisoners were executed for each day he had not completed an assignment to create a more powerful mind-wipe device.
The final fate of the city/compound is not made explicitly clear, but the reversal of the world to a pre-wipe state likely means that the city was reverted to Tucson, Arizona. The technology itself that was present in the city was also likely destroyed by either Adelle DeWitt and her forces, Zone or Echo when she was able to leave the L.A. Dollhouse in 2021.