All of the pits in this stage minus the farthest left and right ones are narrow, providing wall jumpers a decent advantage.
This stage is from EarthBound. Fourside is a major city that Ness has to venture through in order to find the fifth Your Sanctuary location. The mayor of Fourside is an old man named Geldegarde Monotoli. Geldegarde worked in the Monotoli Building, which is the tallest building in Fourside. The Monotoli Building is one of the most important places in EarthBound as it is where Ness and Jeff defeat the evil Mani-Mani Statue (in Moonside) and it is where Ness rescues Paula for the second time. The Monotoli Building features yellow text going down the tower that says "Monotoli" in all caps. In this stage in Melee, the Monotoli Building is the center building and looks somewhat similar to how it was designed in EarthBound and the yellow text saying "Monotoli" is retained. The Monotoli Building in EarthBound also has a helipad that had Geldegarde's yellow helicopter on it. When Ness confronts Geldegarde, Geldegarde lets Ness use his helicopter to get to his next location. When Ness gets to the helipad, Pokey Minch (Ness's former "friend") stole the helicopter and flew away, later crashing it in an area known as the Deep Darkness. In this stage, the helipad and the yellow helicopter are retained. The helicopter flying away could be a reference to Pokey stealing the helicopter; however, unlike in EarthBound the helicopter returns to the helipad. Also, the Monotoli Building is not the tallest building in this stage as taller buildings can be seen in the background. In EarthBound, Fourside also featured buildings that had fire escapes. The building featured on the right looks somewhat like one of the buildings in EarthBound that had fire escapes and the fire escapes themselves are retained. The buildings in the background and the building on the left side of the stage don't resemble any building in Fourside.
After the company logos are shown in the opening of EarthBound, there is a "UFO" sound effect and the game displays an image of three large flying saucers attacking a small town. This is the only time these flying saucers appear in EarthBound as they are never seen in any other part of the game (while there are smaller enemies that are flying saucers in both Mother and EarthBound, these enemies do not look like the large flying saucers seen in this opening). In this stage, the flying saucers that appeared in the opening also appear in this stage and as the saucers enter the stage the same "UFO" sound can be heard from EarthBound's opening.
In EarthBound, Fourside is never shown at night, as much of the game only takes place during the day. However, in Melee, it is always night-time and there is a large moon featured in the background. In EarthBound when Ness and Jeff were investigating Jackie's Cafe in Fourside, they accidentally discover a new area called Moonside, an illusionary creation of the Mani-Mani Statue. Moonside is an area that is opposite to Fourside as it is always black with glowing lights (as an employee of the Dark Moon Hotel says, "Here in Moonside, it's always in the middle of the night"). This stage being in night-time and the large moon in the background could be a reference to Moonside in EarthBound.
The music heard on Fourside is a remix of the track that plays on Fourside in EarthBound (which is EarthBound's "Because I Love You"), combined with the sound effects of caves, strange locations, the first four melodies of EarthBound's Eight Melodies (which are called "Smiles and Tears"), and an excerpt of the track used in EarthBound's Fire Spring
The stage consists of three buildings. The building on the far left is slanted, so items tend to roll off. The Monotoli Building, in the middle, is split into three parts: the top, two small ledges on either side in the middle, and a semi-long edge on the right. The building on the far right is the shortest one with a flat surface. On the far left building, there is a crane with a platform attached to it. It will move to the left a little and over the center of the building. Once in a while a UFO will appear over the left or right building. Characters can fight on top of the UFO, though it has a slippery terrain, giving the Ice Climbers a distinct advantage on it due to their constant traction.
 Tournament legality
Fourside is often banned, largely due to Peach's ability to stall by using Peach Bomber repeatedly in a pit, as well as other ways to camp and stall due to the large size of the stage; the lack of large, flat platforms also hampers fighting between players, particularly in doubles.