Diamond City

Diamond City or commonly referred among wastelanders as "The Great Green Jewel" is a fortified settlement in the Commonwealth. This settlement is based in the pre-War structure of Fenway Park, its distinctive "Green Monster" color visible on the reinforced walls. The city guards can be seen wearing baseball jerseys and catchers' gear, reflecting the location's former use.

Background
Diamond City was founded in the 2130's in Fenway Park, and quickly established itself as a safe haven for settlers of the Commonwealth, thanks to what its residents affectionately referred to as "the Wall". Later decades saw Diamond City grow into the Commonwealth's largest and most prosperous community, as well as a degree of social stratification. Wealthier residents came to live in homes in the settlement's exclusive Upper Stands, overlooking the Lower Field where everyone else strove to make a living.

In 2180, the Commonwealth Minutemen defended the city from an attacking group of Super mutants. This caused the faction's eventual rise to fame.

An incident known as the "Breaking Mask" occurred in 2229, when a man calling himself Mr. Carter arrived. At first, the people of the city warmed to Mr. Carter, but while he was drinking at the bar that occupied the center of Diamond City's marketplace, he went berserk and killed several residents. When security personnel killed Mr. Carter, they discovered he was a Synth created by the Institute. From that moment on, the people of Diamond City lived in fear that they would be covertly replaced by Synths, though such talk was discouraged and ridiculed by the city's leadership. Even so, a number of people began inexplicably disappearing from the city over the following years, a disturbing trend that no one wished to acknowledge.

In 2272, the protectron Takahashi took up residence in the marketplace's old bar and opened Power Noodles, a restaurant that became a staple of Diamond City culture.

By 2282, Diamond City's mayor was McDonough. In that year, he controversially decreed the expulsion of all ghouls from the city. Some ghouls relocated to Goodneighbor, and continued to bear a grudge against both Mayor McDonough and the inhabitants of Diamond City in general, who did little to reverse the decree.

By 2287, some residents came to believe McDonough had been replaced by a Synth, a suspicion exacerbated by Piper, her sister Nat, and their newspaper Publick Occurrences.

Notable loot

 * RobCo Fun - in Nick Valentine's Detective Agency on Ellie Perkins desk.
 * Live & Love - Magazine in the School by the beds.
 * Big Boy - a unique version of the Fat Man (Fallout 4) that contains an extra projectile can be purchased from Arturo at the weaponry stand in Diamond City market.
 * The holotape Gwinnett Ale brewing subroutines can be found in the Colonial Taphouse, on a shelf behind the bar.
 * A copy of the Join the Railroad holotape may be found in a bedroom near the kitchen of the Dugout Inn. It will be on a nightstand next to an alarm clock.
 * Another copy of the same tape can be found in Abbots House on a shelf when you enter the house.

Behind the scenes

 * Atop the press box, five red flags reading "World Series Champions" with the years 1903, 1912, 1915, 1916, and 1918. This implies that following the Divergence, the Red Sox never won the World Series again and the Curse of the Bambino was never broken. In the real world, the Red Sox finally won the World Series after an 86-year drought in 2004. They won again in 2007 and 2013.
 * According to the left field bleachers, the team's retired numbers in the Fallout universe were 1, 4, 6, 11, 13, 21, and 33. Of these, 1, 4, and 6 are actual retired numbers.
 * On the in-game day of some holidays such as Christmas and Halloween the Market will change its design to that of the corresponding holiday themes. i.e. On the day of Christmas it will replace the lights with fairy lights and putting up Christmas trees, and some guards will occasionally comment about Christmas.

Gallery
Diamond City Даймонд-Сити