Dreaming City is a location featured in Destiny 2: Forsaken. The area serves as a major endgame destination and features a raid in the city's core. It is located within the The Reef and is accessible after completing the Forsaken campaign.
One of several secret cities constructed by the Awoken around the Reef, the Dreaming City was their most prized accomplishment, made to emulate and preserve the society brought with the Awoken from the Distributary. The Dreaming City was evacuated prior to the invasion of Oryx. When Oryx killed the Awoken Queen, he became aware of the city and dispatched his Taken there. As of Forsaken, these Taken served the Taken Ahamkara, Riven.
Currently, the City is trapped under a curse laid down by Riven, who acted upon the final, unspoken wish of her killers. The Dreaming City is trapped in a three week cycle, where Taken corruption spreads unabated. Guardians must destroy the source of this corruption, but this merely resets the city to the beginning, along with the Awoken trapped there.
The Dreaming City is an endgame patrol area that becomes accessible after completing the Forsaken campaign. The location will include new public events, activities, and questlines. An activity called Blind Well is a major feature of the area. Groups of three to six Guardians can pledge offerings to a monument that summons creatures to defeat. By defeating enemies, Guardians will unlock new areas and eventually fight bosses at the end of the activity.