Nekravol

Nekravol is the tenth level of Doom Eternal. Having retrieved the Crucible from Taras Nabad, the Doom Slayer travels to the Nekravol intending to use its Argent energy transmitter to reach Urdak and stop the Khan Maykr from resurrecting the Icon of Sin. The Nekravol is actually divided into two parts - the first part sees the Slayer gaining access to the 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 a point of no return - upon entering the slipgate to it, the Fortress of Doom cannot be accessed again until post-game.

Lore
The 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 the Sightless Judge. 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 dumped in the wastelands of Hell, where they transform into demons over time. The Hell essence is then combined with Wraith energy to create Argent energy, which is then transported to Urdak. The factory uses both Sentinel and Maykr technology as it was built by Argenta slaves under the guidance of the Khan Maykr and the Hell priests.

Trivia

 * In the Hellified region of Exultia, the Nekravol can be seen in the distance.
 * The design of the Nekravol was strongly influenced by traditional depictions of the, including especially  by and Tower of Babel by.
 * Depictions of the Nekravol in concept art and on in-game album covers include a carving in relief of the same beastly pentagram which makes up the Demon Keys of Doom 64. This detail is not apparent while in the level itself, however.