The settlement's upper portion was hard to notice, since it was not in a conspicuous area, and only consisted of a medium-sized warren of tunnels and caves, where the quaggoth lived. Six spiral staircases led from the Quaggoth Caverns to the lower portion of the city, the Ring Caverns, which was carved from ancient igneous stone, and which resembled a typical mind flayer settlement. The mind flayers lived in the six Ring Caverns, which each had an outer ring surrounding a circular central plaza, linked by tubes.
As of Year of the Tankard, 1370 DR, the settlement's economy was based on mostly raiding, but also some trading with other enclaves in the underdark. It could sell psionic items and quaggoth soldiers. 
Ch'Chitl was accessible primarily from Undermountain, from Dolblunde via tunnels from Maden's Tomb Tor, and from the catacombs of the House of Stone. Further access points included the hamlets of Bowshot and Gillian's Hill near Daggerford. Denizens of Ch'Chitl could also easily access the trading routes to Skullport, and use those to access Eryndlyn, Gracklstugh, the mines of Mirabar, and other further away enclaves.
In the Year of the Sun Underground, 1154 DR, Ch'Chitl was founded by a cult of mind flayers that planned the settlement as an adjunct to Skullport. Ch'Chitl was ruled by its Elder Concord prior to 1362 DR.
At some point in its history, it was a thriving metropolis of more than a thousand mind flayers, but by the Year of the Tankard, 1370 DR, there were less than 400 mind flayers. In the Year of Wild Magic, 1372 DR, the settlement was only a small-town sized outpost.
The town was ruled by a council of elders after the death of its elder brain. Ch'Chitl was devastated by the Spellplague in 1385 DR and many of the mind flayer were horribly spellscarred. Three of the elders were merged into one being which became the settlement's new elder brain. The remaining mind flayer acquired extraordinary psionic powers from their spellscars.
After the death of the elder brain, the outpost was led by the Concord of Elders (also referred to as the Elder Concord of Ch'Chitl).
As of Year of the Tankard, 1370 DR, the Elder Concord consisted of nine Creedmasters, who normally would have worked with the community's elder brain. However, Thalynsar, the community's only ulitharid, had consumed the elder brain and had become an ulitharlich, acting from within a hidden council of alhoons or illithiliches, the Shadow Concord. Thus, unbeknownst to the living mind flayers of the enclave, the true rulers were Thalynsar the Ulithautarch and the Shadow Concord, whose members each secretly oversaw a Creed in the city. Thalynsar was attended by three nyraala golems at all times.
The Creeds in the city, which were like guilds, consisted of the Abysmals, the Arisers, the Autarchs (a combination of the more traditional Gatherers and Venerators), the Waiters, the Creatives (who bred greater dopplegangers), the Influences, the Raiders (a combination of the more traditional Possessors and Tamers), the Nourishers, and the Thorough Biters.
A mind flayer associated with Ch'Chitl during this time was Sangalor of the Secrets, who had been exiled to Skullport.
- Tsurlanej, an illithilich sorcerer, first elder of the Concord
- Ornolyg, an illithilich wizard
- Fruyshuk, an illithilich cleric of Ilsensine
- Luors'Nallig, an illithilich sorcerer and Monk
- Grishnurok, an illithilich wizard and psion
- Worvinul, an illithilich sorcerer
- Ellistiv, an illithilich psion
- Aulagol the Soothoon, an illithilich wizard, who unbeknownst to anyone engineered the death of the elder brain
Other inhabitants included:
- Ilserv, a mind flayer who was very knowledgeable of the surface world
- Shaun Taunador, a mind flayer who traded poisons in Skullport
- more than 300 mind flayers, many of whom were psions, psychic warriors, or sorcerers
- about 600 adult quaggoth, about half of which were guards and scouts for the illithid
- leaders of the quaggoth who were barbarians or warriors
- Canon sources are contradictory when describing the year in which a githyanki raid fatally wounded the elder brain in control of Ch'Chitl. Two later sources, including The Grand History of the Realms, place it in 1250 DR, but three earlier sources place it in 1362 DR. Because this event has repercussions in the history of the Unseen and Waterdeep, this wiki will use 1362 DR as the accepted date. You can read the relevant discussions here and here.
- Bruce R. Cordell, Gwendolyn F.M. Kestrel, Jeff Quick (October 2003). Underdark. (Wizards of the Coast), p. 134. ISBN 0-7869-3053-5.
- Bruce R. Cordell, Gwendolyn F.M. Kestrel, Jeff Quick (October 2003). Underdark. (Wizards of the Coast), p. 136. ISBN 0-7869-3053-5.
- Bruce R. Cordell, Ed Greenwood, Chris Sims (August 2008). Forgotten Realms Campaign Guide. Edited by Jennifer Clarke Wilkes, et al. (Wizards of the Coast), p. 232. ISBN 978-0-7869-4924-3.
- Eric L. Boyd (November 1999). Drizzt Do'Urden's Guide to the Underdark. Edited by Jeff Quick. (TSR, Inc.), p. 44. ISBN 0-7869-1509-9.
- Adam Lee, Ben Petrisor, Matt Sernett (2016). Tyrants of the Underdark Rulebook. (Wizards of the Coast), p. 16. ISBN 978-1-9408-2585-4.
- Eric L. Boyd (November 1999). Drizzt Do'Urden's Guide to the Underdark. Edited by Jeff Quick. (TSR, Inc.), p. 43. ISBN 0-7869-1509-9.
- Eric L. Boyd (November 1999). Drizzt Do'Urden's Guide to the Underdark. Edited by Jeff Quick. (TSR, Inc.), p. 45. ISBN 0-7869-1509-9.
- Eric L. Boyd (November 1999). Drizzt Do'Urden's Guide to the Underdark. Edited by Jeff Quick. (TSR, Inc.), p. 47. ISBN 0-7869-1509-9.
- Brian R. James, Ed Greenwood (September 2007). The Grand History of the Realms. Edited by Kim Mohan, Penny Williams. (Wizards of the Coast), p. 122. ISBN 978-0-7869-4731-7.
- Bruce R. Cordell, Gwendolyn F.M. Kestrel, Jeff Quick (October 2003). Underdark. (Wizards of the Coast), p. 135. ISBN 0-7869-3053-5.
- Steven E. Schend, Sean K. Reynolds and Eric L. Boyd (June 2000). Cloak & Dagger. (Wizards of the Coast), p. 99. ISBN 0-7869-1627-3.