Earth

Earth, also referred to as "the Ground", was the original home of humanity. The series starts in September 2149, 97 years after a devastating nuclear apocalypse was caused by an A.I. called, "A.L.I.E.". While much of the ground recovered, with vibrant plant and animal life, atmospheric radiation levels remained at a significant level.

Survivors in space believed Earth to be uninhabitable, but after a critical system failure in the Ark's life support systems, the 100 were sent to the surface in a last-ditch attempt to determine if Earth is habitable again. There they discovered that the Grounders have been living on the ground for generations. Throughout the first five seasons, various factions, including Grounders, Sky People, Mountain Men, A.L.I.E., and Eligius prisoners, fight for control of the ground.

At the end of the fourth season, Earth is destroyed by the death wave, with only one fertile valley remaining. However, on April 26, 2156, the valley, is destroyed by the Damocles bomb, leaving the planet completely uninhabitable.

Environment
On May 10, 2052, A.L.I.E. initiated the Nuclear Apocalypse that devastated the planet and drove humanity to near extinction. Over the following 97 years, much of the planet had recovered but became a very different place. Ecosystems changed, landscapes were reshaped, and life adapted. Much of the infrastructure had been destroyed or decayed. Lush forests grew throughout much of the Baltimore–Washington metropolitan area while further north became a wasteland.

The death wave destroyed approximately 96% of the Earth's surface leaving it as charred ruins. However, Shallow Valley was spared and continued to grow lush with plant life, as well as some animals and fish.

The valley was destroyed on April 26, 2156 by the Damocles bomb launched by Paxton McCreary. That left the entire planet a wasteland and uninhabitable. Thirty years later, Earth was still uninhabitable and showing no signs of recovery, causing Monty Green to declare that the Earth would never recover and would be uninhabitable forever.

Major Locations

 * Delinquents' Camp
 * Tondc
 * Mount Weather
 * Arkadia
 * Dead Zone
 * Becca's Island
 * Polis
 * Second Dawn Bunker
 * Shallow Valley

Art Supply Store
Also known as Finn's Bunker, it is the name given to a bomb shelter discovered by Finn Collins. The bunker's original purpose was to serve as a shelter from nuclear bombs in the case of an apocalypse, but the owners never made it. The Delinquents used it for supplies as well as a place to take shelter.

Because of the instability of the Delinquents' society, Finn convinced Clarke Griffin to keep the bunker a secret in order to have a place to hide if the needs arose. In Murphy's Law, when John Murphy was out to get Charlotte, Finn and Clarke hide Charlotte down in the bunker. After Clarke and Finn fall asleep, they wake up to find that Charlotte ran away. Later, Clarke and Finn sleep together in the bunker. After Raven Reyes arrives on Earth, Clarke takes Raven to the bunker in His Sister's Keeper to look for a transmitter to fix the radio. Raven found a remote-controlled car and used it for parts.

After capturing Delano in Reapercussions, Finn takes Bellamy Blake, Murphy, Zoe Monroe, and Sterling to the bunker to question Delano, ending in Finn executing him. Finn returns with Clarke to the bunker one last time in Fog of War when they flee from Acid Fog, coming face-to-face with Delano's corpse.

Lincoln's Cave
In His Sister's Keeper, Lincoln brings Octavia Blake back to his cave to treat her injuries. After Lincoln is captured and tortured by the Delinquents, Octavia helps him escape and he returns to his cave. Octavia meets up with Lincoln again in his cave in Unity Day and together with Finn Collins, they arrange the bridge meeting between Clarke and Anya. In I Am Become Death, Octavia finds Lincoln in his cave, packing up his belongings. He asks her to leave with him but she ultimately refuses and decides to stay behind with the Delinquents. Lincoln returns to the cave in We Are Grounders (Part 2) after outrunning Reapers and runs into Finn who convinces him to use the Reapers as a distraction to help the Delinquents during the final battle.

Oil Rig
Located away from the mainland, the Floukru‎‎ live on an oil rig. They use boats and oil tankers for transportation. It is unclear how Luna found the Oil Rig after she abandoned her conclave.

Seen in "Join or Die" and "Red Sky at Morning". It was abandoned in Season Four after all of Floukru died of radiation poisoning.

Abandoned Bridge
It is a minor location in Season 1. before the nuclear apocalypse.

In Unity Day, It is the place where Anya and Clarke meet. During the meeting, Jasper sees Grounders in the trees. After Jasper realizes that they are aiming at Clarke, he tells her to run and fires at the woods. He manages to take down 2 of the attackers. Anya gets shot, but she gets away. In I am Become Death, Raven makes and plants a bomb on the bridge. Finn, carries her away before she gets blown up. The bomb is hit and it destroys the bridge, harming and killing some Grounders including Tris.

Old Army Bunker
The old army bunker was seen in Day Trip. It is located nearby a body of water and ruined buildings. The depot was designed to hold supplies for a long time, such as guns and blankets. The bunker is full of cobwebs and thus uninhabitable. Most of the supplies are bad, ruined or stolen.

The Ruins


In Day Trip, Clarke and Bellamy come across ruins. They search and find a door to the depot. Inside, they find barrels full of grease and guns. Most of the bullets are stubs unfortunately. Clarke finds blankets but Bellamy isn't impressed. Dax stalks them as Clarke and Bellamy are in the depot.

Parking Garage
Seen in Fog of War, it was found by Octavia. The garage was abandoned, during the nuclear apocalypse, leaving behind many cars. Reapers have access to the garage, as seen when they attack and kill Sgt. Scott and another gaurd when turning on an old Christmas mp3 player. It is then once again abandoned when Octavis and Bellamy manage to knock out Lincoln.

Other Minor Locations

 * Eden's Pass
 * Rendon
 * Farm Station

Residents
According to Becca, about 6.5 billion people were killed in the aftermath of the Nuclear Apocalypse. However, some survivors remained, these included the ancestors to the Grounders, the Mountain Men, and the Sky People. The Mountain Men took refuge in Mount Weather and the Sky People survived in space for 97 years isolated from their former natural environment.

Current

 * None

Former

 * Wonkru
 * Sky People
 * Grounders
 * Spacekru
 * Two Nightbloods
 * Eligius Prisoners
 * Mountain Men
 * Reapers
 * A.L.I.E.
 * Floukru

Trivia

 * At the start of the series, 97 years after the Nuclear Apocalypse, Earth was still irradiated. However, Grounders and Sky People can survive on the ground due to having greater immunity to radiation than pre-apocalypse people.
 * Sky People gained immunity due to genetic engineering and growing up in space exposed to solar radiation.
 * Grounders gained immunity due to natural selection and Nightblood serum.
 * Mountain Men did not go through this process and are extremely vulnerable to the atmospheric radiation on the ground.
 * The apocalyptic bridge in Season 1 was once the Spur 4 Bridge.
 * In Season Four, Earth was ravaged again by the death wave (also called Praimfaya). After five years, in 2155, the atmospheric radiation reduced to habitable level for Grounders and Sky People.
 * During the five years, Nightbloods were the only ones who could live on the ground. Clarke and Madi spent those years living in Shallow Valley while all other survivors either hid in the Second Dawn Bunker or escaped to space.
 * It is unclear how the people from Eligius IV gained increased radiation immunity. While six years after the second nuclear apocalypse radiation is habitable for Grounders and Sky People, it is still significantly higher than it was before the first nuclear apocalypse. Unlike those from Eligius III, they were not given the Nightblood serum. However, they were exposed to solar radiation during their hundred year space journey.
 * In the Season Five finale, Earth was completely destroyed and became fully uninhabitable.
 * McCreary initiated the Damocles Event that destroyed the valley as an act of a scorched earth.