Voi is located about 140 kilometers away from the coastal city of New Mombasa, and on the edge of the Tsavo National Park, the largest wildlife reserve in the region. The town served as the crossroads for railway lines between three Kenyan cities. In Voi, a highway known as Tsavo Highway, or A23, joined with the Nairobi Road which connected the cities of Mombasa and Nairobi. By the 26th century, Voi was a futuristic worker town, and it was filled with mechanical factories and shoreline buildings. A number of water pumping stations managed by the GWC Trans-African Pipelines, such as the Voi Municipal Water Pump House 03 located around 17 kilometers from Voi, took care of the water supply in the town.
In the mid 26th century, Voi was situated beside a large man-made lake, which was connected to an ocean inlet leading all the way to New Mombasa on the coast. This waterway provided a way of carrying large amounts of cargo from the facilities in Voi to the space tether in New Mombasa and other locations around the globe. The shorelines of the lake were filled with warehouses and docking structures; one of the most prominent industrial facilities in Voi was the Factory Complex 09 of the Traxus Heavy Industries. Another facility, Factory Complex 71, was also located nearby on the shores of the lake.
About 100,000 BCE, near the end of the Forerunner-Flood war, the Librarian landed on Earth near the site where the town of Voi would be built millennia later. There, she oversaw the creation and subsequent burying of the Ark Portal structure, which would be hidden for thousands of years to come, and would spend her last days in the nearby region before the Halo Array purged the galaxy of sentient life.
Voi has a long history. The town is centuries old, and was formerly a simple market town. According to local history the name of town comes from a slave trader called Chief Kivoi who settled near the Voi river around the 17th century. There after the town grew as a trade post between the local Taita people, other Kenyan tribes and Arabs. The town started to grow at the end of the 19th century when the Kenya-Uganda railway was constructed. People started to move in to work on the railway and the nearby Sisal estates.
 Covenant invasion
- Main article: Battle of Voi
When the Covenant invaded Earth in 2552, the general region between Voi and Mombasa became their top priority due to the Portal buried underneath it. When the Mombasa Tether collapsed on October 20, 2552, debris rained down upon Voi and the surrounding region. At one point, the UNSC placed a SAM launcher in the vicinity of Factory Complex 09 in Voi. During the following weeks, the Covenant forces occupied the city and placed heavy defenses around their excavation.
On November 17, due to the return of John-117, the UNSC was ready for a counterattack. By disabling a Covenant anti-aircraft battery from the ground, the UNSC would be able to assault the Prophet of Truth's Forerunner Dreadnought resting on the center of the Portal.
The Master Chief arrived in Voi via the Tsavo Highway and joined up with the Arbiter and a large group of Marines. The battle for the city begun with the UNSC attacking entrenched Covenant forces. During the engagement, many surviving workers from the Traxus facilities, armed with recovered UNSC weapons joined the Marines in their fight to liberate Voi. Together they destroyed multiple Anti-Air Wraiths, a Scarab, and the Covenant anti-air gun. With the anti-air forces destroyed, Fleet Admiral Terrence Hood's ships attacked the Prophet of Truth's Dreadnought, until Truth activated the Portal to the Ark and escaped through it, with his fleet following.
After this, a Flood-controlled ship slipped in, and crashed in at the western edge of the city. This ship was full of Flood, and the Master Chief and the Arbiter began to fight this new threat. Under orders from Commander Miranda Keyes, they started to move to the downed cruiser, hoping to destroy it in an effort to contain the Flood. As they neared the cruiser, the Covenant separatist Fleet of Retribution arrived, led by Shipmaster Rtas 'Vadum. The separatist flagship, Shadow of Intent, deployed Sangheili ground forces to assist the humans. Voi was ravaged by the Flood infestation and many Marines and surviving civilian personnel were infected in the ensuing chaos, but the Chief and his surviving allies forged ahead into the heart of the city.
The humans learned that the separatists were looking for the AI construct Cortana, who was supposedly aboard the Flood cruiser. Separating from the Arbiter, the Chief went aboard the cruiser. What he found was not Cortana, but a damaged message left by her. As he was inspecting it, 343 Guilty Spark arrived to repair Cortana. All human and Elite forces retreated to the Shadow of Intent as the fleet glassed Voi, therefore destroying all Flood in the vicinity and preventing the parasite from spreading any further.
Voi was terminated as a result of the excavation event; only a few industrial buildings remained, which were promptly destroyed by the separatists as they cleansed the region of Flood, effectively ending the Battle of Voi and marking the end of the campaign on Earth. After the end of the war, a memorial ceremony was held atop a hill in the remains of the town. As humanity began the arduous process of rebuilding, it was decided that this hillside be kept untouched as a memorial to those fallen in the war.
Voi is a key location in Halo 3. Three successive Halo 3 campaign levels - Tsavo Highway, The Storm and Floodgate, take place in or around Voi. The multiplayer maps Foundry and Ghost Town are also set in or in vicinity of Voi. More specifically:
- Tsavo Highway, the third campaign level, takes place along the Tsavo Highway, leading to Voi.
- The Storm deals mainly with the character assaulting Covenant forces entrenched in Voi.
- Floodgate deals with clearing the Flood from the city. The city is eventually glassed by Covenant separatists.
- The last movement of the Halo 2 Soundtrack is called "The Road to Voi".
- One of the ferries used to transport cargo across the lake is encountered stranded on a beach during the level The Storm.
Concept art of the savannahs of Voi, as seen from Crow's Nest.
Tsavo Highway, leading to Voi.
Factory Complex 71 near Voi.
The Voi Memorial after the end of the war.
 List of appearances
- ^ a b Halo 3, campaign level Tsavo Highway
- ^ a b c d e Halo 3, campaign level The Storm
- ^ a b Wikipedia: Voi
- ^ Halo 3, campaign level The Storm ("We’ve got Anti-Air Wraiths in the next lake bed, Chief!")
- ^ Halo 3, multiplayer map Foundry
- ^ Halo 3, campaign level Floodgate
- ^ Halo 3, campaign level Halo