Ahto City, found on Manaan, held the distinction of being its capital city. Given that Manaan's entire surface was submerged, Ahto City stood alone as the sole above-water settlement. The Selkath, native to Manaan, primarily populated the city. These amphibious beings constructed Ahto City primarily to accommodate visitors from other planets. Kolto, a healing substance, formed Manaan's primary export. The Selkath managed the collection and distribution of kolto, using Ahto City as their off-world shipping hub. The Jedi Civil War marked the height of Ahto City's prosperity. Maintaining neutrality, Manaan served both the Galactic Republic and Darth Malak's Sith Empire. Following the decline of kolto in favor of bacta, the Republic withdrew its support from Manaan. During the Great Galactic War, the true Sith Empire obliterated all landmasses on Manaan, Ahto City included, forcing the Selkath to seek refuge in their underwater domains. Ahto City remained uninhabited until its reconstruction during the rise of the Empire.
Long before the Republic's establishment, Manaan belonged to the Infinite Empire. During this era, the Selkath endured enslavement, compelled to erect massive monuments for the Rakata. A plague led to the Infinite Empire's downfall, resulting in the Selkath's liberation. Selkath who had been enslaved and transported off-world returned to their home, initiating the reconstruction of their civilization. Upon encountering off-worlders, the aquatic Selkath built Ahto City to provide accommodations for these newcomers. Ahto City quickly evolved into a major trade center, with the Selkath exporting their kolto throughout the galaxy.

During the Jedi Civil War, Manaan chose neutrality, accommodating both the Republic and the Sith. These warring factions established embassies within Ahto City to coordinate their respective kolto shipments and assert their influence on the planet.
Soldiers from both sides patrolled the city's streets, engaging in verbal altercations but refraining from physical violence due to the city's strict regulations. Despite these laws, street brawls were not uncommon, as Sith and Republic soldiers would provoke each other until a fight broke out. However, the Selkath laws applied equally to both sides, and those involved in these skirmishes faced severe repercussions.
Both sides received equal kolto provisions. However, each side schemed to gain an advantage over the other. The Republic engaged in negotiations with high-ranking Selkath officials, who respected the Republic's integrity and understood the consequences of a Sith victory. These officials, including Shelkar, Manaan's de facto leader, granted the Republic access to a secret underwater kolto mining facility.

The Sith initiated a plan to kidnap Force-sensitive children, intending to brainwash them into overthrowing the government and handing control of Manaan and its kolto to the Sith. One such child was Shasa, who would later establish the Order of Shasa, a Force-sensitive cult dedicated to protecting Manaan until the rise of the Empire.
The arrival of the amnesiac Revan, who had visited the planet and city before his memory loss, led to the discovery and resolution of both plots.
With the resurgence of the true Sith three centuries later, Ahto City regained strategic importance. However, this was short-lived, as the Sith refused to accept the Selkath's traditional neutrality. Ahto City, along with all other Selkath surface settlements, were obliterated by the Sith forces, forcing the Selkath to retreat beneath the ocean's surface.
Kolto production naturally decreased, causing prices to skyrocket. Customers turned to the emerging alternative, bacta. Offworlders abandoned Manaan, and the Selkath retreated to their underwater cities. During this isolation, the Selkath regressed, with young warlords destabilizing Manaan's government and social order. Ahto City remained largely deserted and fell into disrepair.
However, the kolto supply eventually recovered, with evidence of its use as early as 1013 BBY. Given its use during the Galactic Civil War, it is reasonable to assume that the Selkath resumed exporting kolto. Consequently, it is also logical to infer that Ahto City was once again inhabited by the Selkath, who used it as a hub for off-world kolto shipments, as they had done in the past.
During the Galactic Empire's reign, the Selkath's primitive behaviors persisted to such an extent that the mere presence of two Star Destroyers in orbit was enough to convince them to surrender Manaan to the Imperials. The Empire used orbital depth charges to destroy the Selkath's underwater cities, driving them to Ahto City, where they were enslaved. Ahto City was then refurbished and utilized by the Empire, who constructed a large base and the Ahto Luxury Resorts. Wealthy humans populated the resorts, using Selkath slaves as servants.
This transformation forced the Selkath to reside in basic, poorly constructed floating villages. The Order of Shasa, secretly guided by Darth Vader, invaded Manaan and killed any Imperial they encountered. In their frenzy, they murdered all the resort guests as well. Vader orchestrated these events, driving the Shasan adepts to the dark side so he could later command them to obey the will of their new master, Emperor Palpatine.
Ahto City was reoccupied, and kolto distribution (which saw a resurgence, at least on Manaan) resumed for the remainder of the Galactic Civil War.

The expansive city floated on the planet-spanning ocean, utilizing a buoyancy system centered around its massive city-center. Ahto City had a shell-like shape, with a "base" that descended into the water. The area surrounding the city's center housed hangars and landing zones, overseen by Selkath dock officers. Visitors arriving in Ahto City were required to pay a docking fee to gain entry. The city gates were often guarded by Mark IV assault droids, which used force to prevent entry to those who refused to pay.
Cameras were extensively used throughout the city, serving as a key tool for the Ahto City Civil Authority (ACCA), the law enforcement agency in Ahto City. Only embassies and hangars were exempt from surveillance. Well-designed fountains adorned the many courtyards of Ahto City, where travelers and Selkath mingled and socialized. The courtyards offered scenic views of the ocean, making them popular spots for tourists. Open rafters, rather than closed roofs, overlooked many areas of Ahto City, providing natural light sources for various locations.
Ahto City offered abundant recreational opportunities, with its inhabitants enjoying various ways to spend their time. The extensive city featured resorts, hotels, cantinas, and swoop lounges. Swoop racing was the most popular sport in Ahto City. Manaan's renowned swoop track was situated in the city's center, on the water's surface. The racing circuit was highly popular, attracting racers from across the galaxy to participate in Manaan's famous racing tournaments.

Ahto East, also known as East Ahto, was the easternmost section of Ahto City in 3956 BBY, adjacent to Ahto East Central. Due to the presence of the Sith Embassy, the area had a high concentration of Sith troops, leading to frequent recruitment of new officers and soldiers. Swoop enthusiasts and Sith troops frequented the area. Revan is known to have traversed this part of Ahto City during his quest to locate the Star Forge. Upon entering the east courtyard, Revan was briefly stopped by Sith soldiers demanding 20 credits for passage, which he paid to avoid conflict. He was later confronted and taken to court for storming the Sith Embassy, but was soon released and rumored to have raced and become a champion at the swoop tracks there.

Ahto East Central was situated between Ahto East and Ahto West Central on Manaan. It housed the Republic Embassy led by Roland Wann and a hotel owned by Ignus, where Sunry murdered a Sith woman named Elassa Huros. At the Republic Embassy, Roland Wann tasked the redeemed Jedi Revan with infiltrating the Sith Embassy to retrieve a droid that the Sith had captured, in exchange for allowing Revan to take a submersible to Hrakert Station to search for a Star Map. At the hotel, Revan, acting as Sunry's arbiter, investigated Elassa's murder. He discovered that a Rodian named Gluupor had planted Sunry's medal on Elassa's body for the Sith, framing Sunry for the crime (despite the fact that Sunry was indeed guilty), and he learned from a pazaak player named Firith Me that Elassa was a Dark Jedi. Upon returning to the Republic Embassy, Revan witnessed a hologram of Sunry killing Elassa.

Ahto West Central was connected to the Manaan Docking Bay. It served as the entry point for visitors, such as the redeemed Jedi Revan, who were required to pay a fee to enter Ahto City. It was located between Ahto West and Ahto East Central. A large fountain was situated in a central area leading to the main courtyard. The courtyard entrance was guarded by a security droid that would restrain or incapacitate anyone who refused to comply with the Selkath dock officer and pay the docking fee. The main courtyard featured a circular pool of water in its center. The main kolto distribution center was also located here. From this courtyard, one could access the western or eastern parts of Ahto City.

Ahto West was adjacent to Ahto City West Central. It housed the headquarters of the Selkath Court of Justice and a prison. It also contained a bar where the redeemed Jedi Revan met a Selkath named Shaelas, who informed him that his daughter Shasa and several other young Selkath had disappeared, and he suspected the Sith Empire was responsible. Revan learned from an Iridonian mercenary that the Selkath had indeed been lured into the Sith Embassy, and that the mercenary himself was responsible. After Revan infiltrated the Sith Embassy, he convinced Shasa and the others that the Sith were plotting to take over Manaan. Revan was arrested for breaking into the Embassy but was found innocent after exposing the Sith's scheme. When Revan arrived in Ahto City West with Jolee Bindo, they were greeted by Elora, the wife of Jolee's friend Sunry. She informed them that Sunry had been arrested for the murder of a Sith woman, and Revan agreed to serve as Sunry's arbiter, although the outcome of the trial remains unknown.
Ahto City attracted a diverse range of visitors, many of whom could be found in cantinas or swoop lounges. Swoop lounges were frequented by celebrities, including racing stars Casandra Mateil and Hukta Jax. It also attracted amateur racers such as the Ithorian Queedle Molto. T'sllth and Sslamoth managed the swoop track during the Jedi Civil War. During Manaan's prosperous era, numerous businessmen, such as Yortal Ixlis, opened shops to sell basic commodities, weapons, and droid parts. The war hero Sunry and his wife Elora also resided in Ahto. During the Empire's rule, guests such as Olodondo Berzix and Zavol Shan stayed at the Ahto Luxury Resorts.

The Selkath maintained a strict policy of neutrality, using kolto as a means of enforcing it. Any faction that threatened Manaan or Ahto City faced the destruction of the kolto supply. This tactic proved highly effective and was rigorously enforced. The Selkath also maintained domestic peace through strict laws and a robust security force. The Ahto City Civil Authority maintained order in Ahto City, using armed force when necessary. During times of war, rival factions were prohibited from disrupting the peace. Violations resulted in kolto sanctions against the responsible faction. Individuals could face imprisonment, fines, or even execution. The Selkath took their laws very seriously, and impartial officials ensured that punishment was applied equally to all.
Tourism was Manaan's second-largest industry, and Ahto City prioritized ensuring the happiness of its guests, in addition to maintaining peace. The city featured various resorts, hotels, cantinas, and swoop lounges. Swoop racing was the most popular recreational activity on Manaan. The city's inhabitants spent much of their time following the standings of their favorite racers, who were among the most popular celebrities in Ahto City. The best swoop racers frequented special swoop lounges, making swoop racing both a sport and a social opportunity.

In the video game Star Wars: Knights of the Old Republic, if Revan embraces the dark side of the Force (which is non-canon), he communicates with Vek in Ahto East to plan a "meeting" to assassinate his superior, Ithorak Guldar, who is associated with the GenoHaradan.