Megaton

Megaton is a sprawling settlement in the Capital Wasteland, set in and around a crater with a Megaton class unexploded nuclear bomb at its center, giving the location its name. The town of Megaton is protected by large metal walls made from various scavenged materials, primarily the scraps of old pre-War airplanes, which were assembled and reforged together several decades ago by the founders of Megaton in an effort to make the town safer. With 28 named inhabitants and several unnamed Megaton settlers, it is rivaled only by Rivet City in population.

Beginnings
Megaton's crater was first settled 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 the vault's policy. Locked out of the vault, 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 up as building materials for the town. Because Megaton's construction was aided by the Children of the Atom, who worship the undetonated atomic bomb at its center, the settlers had no choice but to leave it unmoved in exchange for their much needed 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 in his office.

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 occupied the nearby Springvale elementary school, intending to tunnel from the school basement into Vault 101. A group, led by Boppo, staged a raid on Megaton, but the attack was foiled when Boppo was shot in the head and killed by the town's sheriff, Lucas Simms. The raiders did not leave the area, though, choosing to remain at the Springvale School, although their mining operation stopped when they opened a nest of giant ants.

Layout
The city of Megaton has been built in a steep-walled crater around an undetonated atomic bomb which rests in a small puddle of radioactive water at the bottom of the depression. This gives the city two roughly circular levels centered on the bomb. The main gate consists of two old aircraft wings and a jet engine which can be opened and closed to protect the only entrance/exit to the town.

If you follow the entry path to the bottom of the depression the Megaton Clinic will be on your right and The Brass Lantern on your left. Just past the bomb to the right is the Church of the Children of Atom and past it to the left lies Mister Burke's house. Confessor Cromwell can usually be found here sermonizing from the puddle to random settlers.

If you turn right when you first enter so that you are still on the lip of the crater, the "path" will take you past Lucas Simms' house, around the Water processing plant, down to Craterside Supply, then back up to the Men's restroom, Moriarty's Saloon and Billy Creel's house. Going down the ramp from there will take you around Nathan and Manya's house (a bus) and to the Women's restroom. Craterside Supply can also be easily reached by taking the ramp directly to the right of the Megaton Clinic.

If you instead turn left at the upper lip, you'll find a locked house (which can be yours if you deactivate the central atomic bomb), followed by Jericho's house. From there, going down will take you to Lucy West's house while going around to the left will get you to the end of the right hand path.

The Megaton armory (very hard lock) can be reached by going up the ramp and around the Church of the Children of Atom to the right or by going down the hill starting from the back door of Moriarty's Saloon. There are strong enemies inside. Prepare with strong weapons and armor before entering.

The common house can be reached by going around the Women's restroom to the right or by passing behind Moriarty's Saloon rather than going around the front past the entrance to the Men's restroom.

In front of the city, outside the walls, you'll find a caravan stop, Micky the water beggar, and Deputy Weld. Behind the city, near the south west corner is the hollowed-out rock.

Megaton ruins
If you revisit Megaton ruins after blowing it up in The Power of the Atom quest, Deputy Weld's head with an orange (or purple) eye will be nearby, sticking out of a pile of debris. He says, ironically, "Welcome to Megaton. The bomb is perfectly safe. We promise. Please hold," in a garbled voice that sounds broken. The sky will be green, and, if you started the Wasteland Survival Guide quest, Moira Brown will survive as a ghoul and appear to tell you that she is relocating to Rivet City. If you have not started the quest, Moira can still be found in Underworld. However, the Strength Bobblehead will be unobtainable if you detonate the bomb before retrieving it. The area around Megaton will contain higher levels of radiation the closer you get to the town's ruins

Notable loot

 * Bobblehead - Strength inside Lucas Simms' house, on a desk in a bedroom on the second floor.
 * Grognak the Barbarian and a Chinese officer's sword in Jericho's house, on the floor, between a teddy bear and a red pylon along the right wall.
 * 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) and a scoped .44 magnum in the floor safe.
 * Sniper rifle, Stealth Boy, .308 caliber rounds, 2 stimpaks and the As Requested note in the hollowed-out rock located outside Megaton along its southern wall. Look for the 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).
 * Chinese Army: Special Ops Training Manual and an ammunition box can be found in a ruined farmhouse to the east, between Megaton and Super-Duper Mart.
 * A rolling pin, a rather hard-to-find and mostly cosmetic weapon (low-damage) can be found in the water processing plant.

Appearances
Megaton appears only in Fallout 3.

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 worshiping 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 for a town with a nuke at its center.
 * In the Japanese version of Fallout 3, Burke is completely gone, and therefore, 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.

Bugs

 * Right after leaving Vault 101 the sky and surrounding area may look as if the bomb has already exploded.
 * After Broken Steel is installed, if you pick-up the note from your door, after completing quest Holy Water, the note will respawn every day. This can be very annoying, and it is recommended to achieve the note from a settler.
 * Upon leaving Vault 101 Megaton may not spawn. To fix this, restart your console.
 * Occasionally the player will be shot at by the settlers of Megaton upon first entering, which can be rather troublesome for a low level character.
 * Occasionally upon entering Megaton with Fawkes accompanying you, he will randomly start shooting everyone in sight.
 * In front of Megaton, where merchants are usually standing, if you drop a small item (such as stimpak) it will seem to disappear, but will not fall through the map.
 * Sometimes when entering Craterside Supply, All the people in there will fall through the ground.(including you)