Megaton

 is a sprawling settlement set in and around a crater with a unexploded nuclear bomb at it's centre. It is protected by large metal walls made of various scavenged materials, primarily the scrap of old pre-war airplanes. It is one of the two largest settlements in the Capital Wasteland, with 28 named inhabitants and several Megaton settlers, rivaled only by Rivet City in sheer size of population.

Beginnings
Megaton was built by a large group of people who sought shelter in Vault 101 but were denied access because the residents of the Vault were not allowed to leave or let anyone in as part of their subterranean installation's policy. Locked out of the Vault, the people settled down around a large crater with a C-23 Megaton atomic bomb in it. These settlers, led by Manya Vargas' father, constructed their homes using aircraft debris from a nearby air station. The Air Station is no longer visible since all of its parts were used for the creation of the town. Because the town's construction was aided by the Children of the Atom, who worship the undetonated bomb, the settlers had no choice but to leave it unmoved in exchange for their help.

First contact with Vault 101 and raider attack
In February 2241, an expeditionary party of Vault 101, led by Anne Palmer and sent by the Overseer of the Vault, made contact with the residents of Megaton. Initially, the locals were cautious of the strangers before eventually accepting and welcoming them into their settlement. Palmer appointed two Vault residents, Agnes Taylor and Lewis, as Vault ambassadors to Megaton. A record of this expedition was archived in the Overseer's terminal.

That same year, a group of raiders attacked the town, resulting in the death of the 14 year old Colin Moriarty's father. After the raid Moriarty inherited his father's wealth and his bar, Moriarty's Saloon.

Boppo's raid
In 2277, a gang of raiders occupy the nearby Springvale Elementary School, with the purpose of mining their way into Vault 101. Some of these gang members, led by Boppo, attempted a raid on Megaton. However, the attackers could not breach Megaton's defenses, and the town's very own sheriff Lucas Simms shot Boppo in the head, killing him, albeit getting shot and injured himself.

Layout
Megaton is roughly circular, with a central plaza around an atomic bomb resting in a puddle of radioactive water. Starting in the north and proceeding clockwise, the plaza is ringed by The Brass Lantern, Mister Burke's House, Church of the Children of Atom, and Megaton Clinic. Pathways lead from the plaza to the gate of Megaton, Craterside Supply and the common house. A major attraction of the plaza are the sermons of Confessor Cromwell.

Around the central buildings, a ring of buildings is built higher up in the crater. The Water Processing Plant and Moriarty's Saloon can be found here along with most of the inhabitants' private houses.

The left side of town is mostly residential, whereas the right side is mostly commercial.

Outside and around the back of the city is the Hollowed-out rock.

Megaton Ruins
After blowing up Megaton in The Power of the Atom, Deputy Weld's head with an orange eye will be outside. Deputy Weld ironically says "Welcome to Megaton. The bomb is perfectly safe. We promise. Please hold." in a garbled voice that sounds broken. The sky will be green, which is strange if you go there immediately after blowing it up, as it should be red first. If you started the Wasteland Survival Guide quest, Moira Brown will survive and come outside and talk to you, as a ghoul. If you have not started the quest Moira can be found in Underworld.

Notable loot

 * Bobblehead - Strength inside Lucas Simms' House, on a desk in a bedroom on the second floor. To avoid bad karma from picking the lock, wait until Lucas or his son are in his home or by entering the house through a hatch on the roof, or take the key from his dead body.
 * Grognak the Barabarian in Jericho's House, on the floor, between a teddy bear and a red pylon. You have to steal this item.
 * Nikola Tesla and You in your Megaton home after buying the science theme from Moira Brown.
 * Lying, Congressional Style in your Megaton home when you buy the Love Machine Theme from Moira Brown.
 * 4 pre-War books in Billy Creel's House, must be stolen.
 * Sniper rifle, stealth boy, .308 caliber rounds, 2 stimpaks and the As Requested note located outside Megaton along its southern wall. Look for a hollowed-out rock with three small trees in a triangular pattern around it.
 * 300-700 bottle caps in the Brass Lantern. A terminal (very easy) unlocks a floor safe which is otherwise locked (average).

Appearances
appears only in Fallout 3.

Bugs

 * Once you leave your house, a Megaton resident may spawn in front of you, causing the game to freeze.
 * Right after leaving Vault 101 the sky and surrounding area may look as if the bomb has already exploded.

Behind the scenes

 * The bomb in the center of the town and the people worshiping it are likely a reference to Beneath The Planet of the Apes, which features a cult worshipping an undetonated nuclear weapon after the modern world has been destroyed.
 * A Megaton is used to measure an explosion equivalent to the force of a million tonnes of TNT- A fitting name to a town with a nuke in the town center.
 * In the Japanese version of Fallout 3, the quest to blow up Megaton has been completely removed due to its "parallels to real historic events" . Referring to the atomic bombs that were dropped on Hiroshima and Nagasaki in 1945.