Nekravol

Nekravol is the tenth level of Doom Eternal. Having retrieved the Crucible from Taras Nabad, the Doom Slayer travels to Nekravol intending to use its Argent energy transmitter to reach Urdak and stop the Khan Maykr resurrecting the Icon of Sin. Nekravol is actually divided into two parts - the first part sees the Slayer gaining access to Nekravol and traversing its lower levels, while the second part sees the Slayer climbing to the top of the facility to reach the transmitter.

This level is the point of no return - upon entering the level, the Fortress of Doom cannot be accessed until post-game.

Lore
Nekravol is a titanic Hell city, referred to both as a factory and a fortress. It serves a very important role: the creation of Argent energy for Urdak.

The creation of Argent starts with the sorting of Hell's victims by Kalibas. Humans who are deemed unworthy to be processed further are discarded into the Blood Swamps. Those who are worthy are taken further into the facility and tortured until their spirits are broken, at which point their souls are extracted by the Evulsor and turned into Hell essence, while their bodies are left in the wastelands of Hell, where they transform into demons over time. The Hell essence is then combined with Wraith power to create Argent energy, which is then transported to Urdak. The factory uses both Sentinel and Maykr technology because it was built by Argenta slaves under the guidance of the Khan Maykr and the Hell Priests.