This is a list of known locations on the Gem Homeworld and other planets controlled by Gems.
Homeworld appears to be split into two sections: an upper level and a lower level. The lower level (the surface of Homeworld) is barren and lifeless, likely because the Homeworld Kindergarten drained the life force out of the planet. The upper level is where modern day Homeworld cities and structures appear.
Homeworld is home to a highly advanced city. Skyscrapers can be seen with thin white tubes connecting them. Lights of different colors can be seen travelling through these tubes. There are also white pedestals with red inverted triangles on top. At the bottom of one of the skyscrapers are cell-like structures, very similar to the cells inside of the Gem Warship. There is a white flower-like mechanism in the city attached to an anvil and a circular black structure on top, bearing resemblance to the shape of a Roaming Eye ship. In the distance, green tubes can be seen connecting to triangular structures, and there are also black inverted pyramids which are identical to the Pyramid Temple on Earth. A large structure built in the shape of the White Diamond can also be seen in the distance.
- Docking Bay : There is a building near the city with a lime green interior. Gems enter the docking bay to park and exit ships.
- Trial Building: While it is unknown if the trial building is in the same building as the docking bay, it is also located in this city. There is an empty pink room for the defendant to stay in until their trial, which connects to a trial room, where court cases take place. The exterior of the building is black and the shape of the Roaming Eye.
- Deep Cavern: Below the trial building is a large, gaping hole in the ground. It is surrounded by walls of different shapes, taking on strange appearances compared to structures on Earth. Notable wall designs have a similar appearance to cheese graters. These holes bear resemblence to the cells aboard the Gem Warship, and those seen under the Ancient Sky Arena. The cavern also has white tubes with different colored beams flowing through.
At the bottom of the cavern is the abandoned surface area of Homeworld. Being partially underground, (due to above ground structures) the area receives little light, and is very dark. The area is barren, covered in dirt and rock. Many green tubes connect the walls together closer to the ground. Pedestals protrude from the ground, and old statues of Gems and fusions can be seen scattered around. Some pedestals have text on them written in the Gem Language. There is another hole in the ground that leads to an abandoned Kindergarten facility.
- Abandoned Kindergarten: Going through another hole in the ground leads to a dark cave. At the end of the cave is a humongous Kindergarten, with holes scattered everywhere that are seemingly endless. Going through a entryway in a wall leads to another part of the Kindergarten, where the Off Colors live. This Kindergarten is completely underground.
Yellow Diamond's Unknown Moon Base
Not much is known about the Moon Base's location, aside from the fact that it appears to be near or inside of an asteroid field.
In "Message Received", Yellow Diamond is seen in the control room using holographic terminals to access information quickly. These terminals presumably possess the same functionality as the Moon Base terminals.
Only a white floating chair atop a stepped diamond-shaped altar can be seen from the inside, seemingly where Yellow Diamond works. There is a large glass wall made up of triangular panels separating the control room from the outside where several asteroids float in space both near and far.
Gem Controlled Planets & Moons
Other various planets and moons which have been conquered by the Homeworld Gems are often shown in murals on various Gem structures. Only two have actually been named so far.
Upsilon is the 20th letter of the Greek alphabet, which has a value of 400 in the system of Greek numerals. The symbol of Upsilon (Y or u), or variations thereof, has been used for particle physics and linguistics, among other things; in the context of astrophysics and physical cosmology, a symbol of Upsilon refers to the mass-to-light ratio (the quotient between a spacial volume's mass and it's luminosity). It is also known as "Pythagoras' letter" or "the Samian letter", as Pythagoras used it as "an emblem of the path of virtue or vice."
Klavius 7's name may be inspired by the Clavius crater, one of the largest crater formations on Earth's moon, which was named after 16th century Jesuit priest, mathematician, and astronomer Christopher Clavius. Clavius is also the name of a fictional lunar settlement in Arthur C. Clarke's Space Odyssey literary universe, located in the same crater formation.
A planet located in Sector 7 which was colonized by Yellow Diamond a long time ago. The planet itself is now mostly hollowed out and completely devoid of life.
The moon which orbits the planet is still covered by a thick jungle and organic life. The Moon Base that was constructed on its surface is now abandoned and damaged by plant growth.
Yellow Diamond's Asteroid Mines
Yellow Diamond controls a number of asteroid mines, presumably guarded sites containing materials for Gem technology.
It is revealed in the episode "Lars of the Stars" that different areas of space are referred to as "sectors" by Homeworld.
- Sector 4 – The location of the planet Klavius 7 where the Sun Incinerator departed and jump to hyperspace.
- Sector 7 – The location of the unknown planet and its jungle moon where Stevonnie was stranded after their conflict with Emerald.
- Three unknown sectors – Mentioned to have been passed through by the Off Colors.