Nergal was built on a city that formerly existed prior to the Second Great War. When the city was destroyed, Vilebluysk was intimidated into joining the Coalition in its infancy. Due to a massive magma chamber under the city, the demons built a large forge and around it an underground city. The city was the base of operations for the demon army during the early assaults on Euclid, before demons began to integrate into society and begin their own. The Coalition built a stone city on top of the demon headquarters, naming it 'Nergal.' Around one hundred years prior to The Demon's Light, Cicero and the other Coalition leaders began construction on a top layer to the city, which would house the industrial district and draw attention from the classified creation of airships.
Nergal is layered as a series of 'shells.' The upper shell, also known as the Industrial District, is a massive dome made of dark metals. The dome's interior is filled with factories and the exterior covered in airship ports. On the coastal end of the city, there is a large port for both industrial and military ships. The area around the dome is more of a conventional city, full of apartments, mansions, and shops. The upper shell's architecture is done in an Art Deco style, and also contains Cicero's palace at the top of the dome.
The upper shell is surrounded by the remnants of the city that once stood where Nergal does now. The rubble has become mostly ingrained with the landscape, appearing more like bizarre formations of stone than a city. It is home to numerous cults to the different Powers and other legendary figures on Euclid and Eden.
Underneath the upper shell is central Nergal, which holds a majority of the city's population. The architecture is far less advanced, with crude limestone pillars lining the stone city. There are three rings through the city, encircling each other and acting as railroads for transportation. Nuyövian influences are at their most common in this area of the city. Central Nergal is notable for its unconventional city design, automobiles being illegal and resulting in the streets being thin and winding.
Beneath central Nergal lies lower Nergal, a dark, cavernous area home to a majority of the demon population of the city. Lower Nergal itself has three levels, each a layer of stone above the magma chamber that lies beneath Nergal. The highest layer, Ikalla, is home to both the residential and market districts. Underneath Ikalla lies 'the Bascilla of Divine Whispers', which is home to the demons' governmental and military bases as well as the city's religious institutions. Within the Bascilla is the smaller Necropolis District, where the dead are buried and revered. Lower Nergal is built out of dark, twisting stone with intricate carvings.
The final layer of lower Nergal is known as 'the Teeth that Gnash', and it is built directly above the pit of magma. the Teeth are known to those above as the 'Forge District,' due to the fact that it is exclusively populated by metalworkers who use the magma chamber to forge armor, weapons, and other objects. There is little to no competition between the inhabitants of the Teeth, and they are among the most respected class of society.