- "Well, the COG used it as a field hospital. Actual fort is from way before the COG. Seriously, like kings-and-wizards days. Hey listen, I'm trying to give you some enriching historical context here."
- —Lieutenant Del Walker 
Fort Reval was a sprawling, ancient fortress in Tyrus. Twenty-five years after the end of the Lambent Pandemic and Locust War, JD Fenix, Kait Diaz, and Delmont Walker fought the Swarm in the rundown fort whilst searching for JD's father, Marcus Fenix.
Fort Reval was originally constructed centuries before the beginning of the Silver Era. The oldest surviving portion of the fort, the foundation beneath its main gate, has been dated to almost one thousand years ago. Initially, the original keep of the fort served as the stronghold of a local warlord. By the time of the Silver Era, the town surrounding the fort had been built and the fort itself had expanded and served as the residence of a Tyran royal dynasty, who interred their dead in extensive catacombs beneath the keep.
At the fort's heyday during the Silver Age, visitors all had to cross its main gate in order to trade, seek shelter, or gain audience with the king, who was safeguarded by guards and soldiers noted in ancient sources as fiercely loyal and the finest warriors of their day. One particular king, known only as "Fort Reval's king", became the most well-known ruler of the fort.
According to an apocryphal Silver Age legend, an assassin who sought to kill Fort Reval's king was captured in a market alley after being tripped by a priest; the alley was thereafter known as "Monktrip Alley". A statue in the fort's main courtyard depicting an unknown bearded figure holding a quill and tablet is argued to be a philosopher, the king's father, or the king himself in priestly clothing. Eventually, Gorasni barbarians invaded the region and assassinated Fort Reval's king under the cover of night.
Presumably, the fort was then abandoned until modern times, before E-Day, when it attracted the interest of Coalition of Ordered Governments archaeologists. The archaeologists heavily restored the fort, converting the customs building into a tram station and the barracks into a military museum. The restoration effort forced a halt to further investigation of the fort's catacombs. The "Fort Reval Historical Site" became a popular tourist destination until the outbreak of the Locust War.
During the war, the COG re-purposed Fort Reval as a military field hospital. After the war, thousands of crystallized Locust corpses and weapons were dumped into a local osmium mine, one of many such Locust burial sites. With the reconstituted COG's focus on protecting the surviving human population in the post-war era, the fort was allowed to fall into ruin. Most recently, its ruins were overrun by the Swarm from the nest in the osmium mine.
With the attack on Fort Umson by the Swarm, Marcus Fenix led his son JD, Delmont Walker and Kait Diaz to Fort Reval to search the Locust burial site for possible connections between the Locust and the Swarm. During the mission, Marcus was captured by a Snatcher which the rest of the team chased through the fort, into the catacombs and from there into the mine. Hours later, power was restored to Fort Reval when the team restored power to Tollen Dam which powered the fort.
- Gears of War 4 (First appearance)