Hell

Hell and The Pentagram is the primary setting of Hazbin Hotel.

Description
Hell is the supernatural realm where the souls of sinners and the damned are sent after death. It is also presumably ruled by the Devil whose daughter is Charlie. Hell apparently suffers from mass-overpopulation which the demons of hell attempt to solve through mass-genocides and exterminations of it's inhabitants but which Charlie attempts to solve through the creation of the Happy Hotel.

Trivia

 * Hell was a location also featured in show-creator Vivienne Medrano's popular web-comic Zoophobia.
 * The setting is based on the location of the same name from Abrahamic Mythology where it is said to be one of 4 afterlife destinations, namely Heaven (for good souls), Limbo (the borderlands of Hell), and Purgatory (borderlands of life and death).