From Grand Theft Wiki

The Mass Grave is commonly misinterpreted as a myth. It is located north of the Restricted Area and south of the Verdant Meadows Aircraft Graveyard. According to some sources, the bodies were dumped there by a serial killer. Inside the grave, which is a large round hole in the ground, are six body bags, next to the grave is a parked truck.

Answer

Although many people choose to link this myth to the 'serial killer' myth, this is, likely, not the case, as two Sindacco Family thugs are seen in the desert digging a grave, and then leaving it in The Introduction that came with the Grand Theft Auto: San Andreas Special Addition, (also including Sunday Driver) although the two goons are only burying one person, not six - possibly indicating that more people were buried there during the events of Grand Theft Auto: San Andreas. This could also indicate that the hole was a popular place for the Families to dispose of bodies.

The Mass Grave along with the "serial killer's" truck

The body bags inside the Mass Grave

The location of the Mass Grave pointed out in a map.

From Lostpedia

Mass grave

[[{{{Video}}}|Orientation Video]]

First seen

"The Man Behind the Curtain"

Last seen

"Cabin Fever"

Constructed by

The Hostiles

Controlled by

None

Connection

{{{Connection}}}

Number

{{{Number}}}

Purpose

{{{Purpose}}}

Status

{{{Status}}}

Discovered by

{{{Discover}}}

DHARMA Initiative Stations
The Hydra • The Arrow • The Swan
The Flame • The Pearl • The Orchid
The Staff • The Tempest
The Looking Glass • The Lamp Post

The Temple

[[:Category:{{{Images}}}|Images]]

The mass grave is an open pit into which the bodies of the DHARMA Initiative staff were dumped after being killed during the Purge. The grave site is roughly half a day's hike from Jacob's cabin.

Following their visit to Jacob's cabin, Ben Linus brought John Locke to the mass grave to show him the place where he "came from". Ben explained that the corpses were members of the DHARMA Initiative, the group he was a member of before he joined the Others. Ben claimed that when it became clear to him that the DHARMA members would be purged, he did what was necessary to stay alive. After this revelation, Ben shot Locke in the abdomen and left him for dead in the pit. ("The Man Behind the Curtain")

Locke came to and prepared to shoot himself with a gun he found on one of the corpses. He was stopped by what appeared to be "Walt, only taller," who instructed him to get up as there was work to be done. ("Through the Looking Glass")

Approximately a week later, Locke returned to the mass grave with Hurley and Ben after being told to find Horace in a dream. Searching through the bodies, Locke found Horace's blueprints containing the location of Jacob's cabin. ("Cabin Fever")

Trivia

• One of the corpses appears to have a gunshot wound to the head, indicating either that the use of toxic gas wasn't the only method used to kill off the members of the DHARMA Initiative or that bodies continued to be disposed of in the pit after the gassing.
• Over forty people were killed during the Purge. ("Through the Looking Glass")

Locations Locations World Locations by City Australia • Egypt • France • Germany • Indonesia • Iraq • Nigeria • South Korea • Tunisia • United Kingdom • United States Flight 815 survivors and Flight 316 survivors Beach camp • Caves • Eko's church • Eko's grave • Garden • Golf course • Graves • Hydra Island camp • Rose and Bernard's cabin • Sweat lodge • Tiger pit DHARMA, The Others and U.S. Army The Hatch • The Staff • The Arrow • The Swan • The Flame • The Pearl • The Orchid • The Hydra • The Looking Glass • The Tempest • The Temple • The Lamp Post • The Door • The ? • The Barracks • Cages • Capsule dump • Decoy village • Hydra Island • Jacob's cabin • Mass grave • Pala Ferry • Processing Center • Runway • Radio tower • The Others' camp • The Incident Room • Tree mark • Army camp • Sonar fence • The Tunnels • Jughead The Island's locations Alex's hideout • Balloon • Black Rock • Cliff • Cove • Dark Territory • Drug smugglers' plane • Statue of Taweret • Frozen wheel • Jungle • Lagoon • Lake • The Line • The Mesa • North Valley • Ocean • Pascal Flats • Polar bear cave • Rivers • Rope bridge • Rousseau's camp • Ruins • Waterfall Off-Island locations Bars • Eloise's church • The Lamp Post • Choogdong Hospital • Commune • Cowin Heights High School • Delerue Center for Rehabilitation • Fieldcroft School • Gus' Pawn Shop • Heathrow Airport • Hotels and motels • Kashmir Curry • LAX • Tracking station • Marina Medical Center Long Beach • Melbourne Walkabout Tours • Membata • Moriah Vineyards • Mr. Cluck's Chicken Shack • La Vida Tacos • Le Portail d'Arabie • Long Beach Marina • Rainbow Drive-In • Safe house • Santa Rosa Mental Health Institute • Smith Stop & Run • Southway Garrison • Simon's Butcher Shop • Sri Lanka • St. Francis Hospital • St. Sebastian Hospital • Stadium • Sydney Airport • University of Michigan