The City of Dis encompasses the sixth through the ninth circles of Hell.
Before the City is reached, in ninth canto, Dante encounters the unbaptised and then those who sinned by self-indulgence—the lustful, the gluttons, the misers and spendthrifts—and at the outskirts of the red-hot walls of City of Dis are the wrathful and those of ill-will.
From this point on we find sinners who acted out of malice and wickedness. Immediately within the walls of the City are the Heretics, who disbelieved in immortality are forever imprisoned in red-hot tombs. Beyond are rings of those who were violent—to others, to themselves (suicides), to God (blasphemers), to art (usurers), and to nature (sexual perverts). Beyond the ruins of Dis are the frauds and corruptors, and finally the traitors.
In ancient Roman mythology, Dis Pater ("Father Dis") is the ruler of the underworld and is named as such in the sixth book of Virgil's "Aeneid", one of the principal influences on Dante in his depiction of Hell (the god was also known as Pluto, a name not used by Virgil in the Aeneid). The hero Aeneas enters the "desolate halls and vacant realm of Dis" with his guide, the Sibyl, who correspond in The Divine Comedy to "Dante" as the speaker of the poem and his guide, Virgil.
The walls of Dis are guarded by fallen angels, the Furies, and Medusa. Dante emphasizes the character of the place as a city by describing its architectural features: towers, gates, walls, ramparts, bridges, and moats. It is thus an antithesis to the heavenly city, as for instance described by St. Augustine in his book City of God. Among these structures are mosques, "the worship places of the most dangerous enemies of medieval Christendom." The presence of mosques probably also recalls the reality of Jerusalem in Dante's own time, where gilded domes dominated the skyline.
Punished within Dis are those whose lives were marked by active (rather than passive) sins: heretics, murderers, suicides, blasphemers, usurers, sodomites, panderers, seducers, flatterers, Simoniacs, false prophets, barrators, hypocrites, thieves, fraudulent advisors, sowers of discord, falsifiers, and traitors. Sinners unable to control their passions offend God less than these, whose lives were driven by malizia ("malice, wicked intent"):
There is perhaps a distinction between malizia as the characteristic of circles seven and eight, and the matta bestialitade, "inhuman wickedness," of circle nine, which punishes those who threaten "the most basic civic, familial, and religious foundations of happiness."