"Fallout 4's" expansive Wasteland is home not just to settlements, raider encampments, and monstrosities, but also to other locations that are enveloped in mystery.

One such location is known as Vault 75, and it's one place that "Fallout 4" players should visit at least once.

In order to find Vault 75, players will first need to pay a visit to Malden Middle School, as shown here on the map courtesy of the "Fallout" Wikia. Once there, players need to head to the school's basement in order to gain access to Vault 75.

Upon entering Vault 75, players will soon begin to understand why this structure was built underneath a school. According to iDigital Times, Vault 75 was designed to house children, or to be more specific, it was made to play host to a variety of different experiments that would be done on its young occupants.

"Fallout 4's" Vault 75 features a variety of different facilities that are intended for kids, including classrooms and various kinds of playground equipment.

It's unclear what exactly the experiments being performed on children were, but the terminals within Vault 75 do indicate that at least more than a few of the children met an untimely demise within the walls of the now forgotten location.

The experiments carried out on the children of Vault 75 were reportedly done in pursuit of creating more advanced human beings, although it appears the efforts did not return their intended results.

Aside from learning about the history of Vault 75, those who will travel to this secret location will also be able to acquire some valuable items in "Fallout 4." Such items include the Science bobblehead found near Vault 75's dining area. There is also a Grognak the Barbarian magazine located in the Overseer's office.

Vault 75 is just one of the many mysterious locations inside "Fallout 4," with more still waiting to be uncovered.