Zolfanello City (Sulfur City or Match City in the English Dub) is the Devils' home. It can also be considered Hell itself where all devilish and evil creatures live without any rules.
Zolfanello City is ruled is by the Low Spheres, whose faces are never shown and their voices are the only thing that are heard through the entire series.
The city of devils, unlike the city of angels, isn't that much like a human city, it's filled with volcanoes and seas of lava however like a normal city it contains shops, bars, discos, transfigured however possesses a devilish look and is stuck to the ground, among dust and sulfur smoke. At the service of the Low Spheres are the Malebolgie ("Malebolges" in English) and the Diabolic Army.
Low Spheres Tower
The Low Spheres Tower as its names says, is the tower where are located the Low Spheres, the place where Devil teachers go in order to report to the Low Spheres how things are going in the students' stage. Unlike the High Spheres Tower that does appear once in the series, the Low Spheres tower is never shown from the outside and the only room from that tower that is shown is the Low Sphere room.
From the inside, the tower has got a round shaped floor and walls made of rocks, at the middle of the room the floor is broken and that hole is filled with real lava that however does not burn any of the rocks of the room. In the center of the lava hola is a floating rock which is the place where the teachers go when they are talking with the Low Spheres. The room is sustained by long and large, royal blue and golden columns which are set at the doors of the Low Spheres. The number of doors of the leaders of the Devils are, like the High Spheres', five.
The Mortal Portal
The Mortal Portal is the portal, equivalent to the Angels' Big Door, that every year thousands of devils must cross in order to go down to Earth. It is a big reddish-brown rock structure, build in the middle of many other rocks and inside the structure is a grey metal door. The Mortal Portal is guarded by a Guardian Devil, he holds in his hand a spear that he uses to keep intruders from entering the city. Unlike in Angie Town, in order to enter the city the devils
must say a password: Red Horn. That was revealed on 2x38 when Raf and friends, under desguise of devils, try to enter in the city and remember that Sulfus told them the password. The Guardian however is somehow deaf and either real or fake devils can get in trouble if he hears wrong the password.
The Rainbow Crypt
The Rumbling Tomb