The club is located in the basement level of a building in Mega City. The entrance is guarded by armed supernatural programs with gravity-defying capabilities. (The belief is that these Exiles are Vamps/Blood-Drinkers, since they have shown the ability to move across any surface, standing up; on more than one occasion.)
The club is a depiction of a fetish nightclub, filled with stereotypical members of goth, punk, and other modern subcultures. Some of the patrons even appear to be engaging in heterosexual and homosexual acts of a sexual nature. It is similar to the club in which Neo first met Trinity. The patrons are Exiles in fact, and their attire and mannerisms are tied into the supernatural beings they are supposed to be emulating (two Exiles standing guard to The Merovingian's balcony look like Satyrs, or possibly Minotaurs, even if they are bondage/fetish Gear). A majority of the Exiles present are Vampires, Lupines, and other creatures from previous versions of the Matrix.
Morpheus, Trinity and Seraph defeat these guards before proceeding to the inner chamber. Here they meet with the Merovingian to barter for Neo's escape from Mobil Avenue station, a computer construct run by The Merovingian's henchman, The Trainman. After Trinity starts a fight and creates a Mexican standoff with the Merovingian, Neo is freed.
The name is actually drawn from the realm of Hel in Norse Mythology, where a goddess by the same name ruled over the spirits of those who died ingloriously and those who broke oaths. Similarly, the Merovingian does many dealings with the Exiles in the Matrix universe, the programs who have broken their oath to report for deletion.
Similarily, the club is a representation of the underworld and the ruler of the underworld in Greek mythology is Hades. The Merovingian parallels with Hades and his club is his underworld or 'Hell'.
In the elevator that Trinity, Morpheus and Seraph take to the club, there is a brief shot of the red "Help" button on the control panel. The "P" on the button has been scratched out so it reads "HEL".