Galaxy Warp

"Galaxy Warp" is a large Gem structure that is first mentioned in "Mirror Gem" and makes its first appearance in "Space Race". It's appears in Steven Universe.

About
The Galaxy Warp is the former central hub on Earth for interstellar transport through the galaxy used by Gems, replacing the Colony type ships. The system consists of numerous Warp Pads of varying sizes that have been inactive for thousands of years. The Galaxy Warp is located atop a large plateau, surrounded by an ocean or large lake and numerous smaller islands.

Six massive crystalline rock formations surround the perimeter of the summit, which houses sixteen individual Warp Pads arranged in a crop circle-like pattern. The central pad directly links Earth with the Gem Homeworld.

As of "Friend Ship", part of one of the rock formations has collapsed due to Peridot's attacks. In addition, another Warp Pad was completely destroyed in an attempt to capture Peridot.

"Mirror Gem"
The Galaxy Warp is mentioned in "Mirror Gem". Lapis' mirror was retrieved from there.

"Space Race"
The Galaxy Warp makes it first appearance in the episode as the Crystal Gems are checking up on it, using Steven's Crying Breakfast Friends stickers to mark its inactive warp pads.

"Warp Tour"
The Crystal Gems follow Peridot's robonoids back to the Galaxy Warp where they proceed to repair the Homeworld warp, allowing Peridot to warp there. She then hastily retreats upon discovering one of the stickers, believing the site to have been "compromised". Garnet then increases the size of her gauntlets and proceeds to smash the Homeworld warp pad with them, effectively cutting off travel to and from Homeworld via warping.

"Winter Forecast"
While not featured in the actual episode, Steven discovers through his future vision that the Gems launched the Shooting Star directly to the Galaxy Warp with the objective of destroying it once and for all.

"Friend Ship"
The Galaxy Warp appears to be untouched by the Shooting Star. Peridot was seen attempting to repair the Homeworld Warp before fighting the Crystal Gems and later using the only active warp pad to escape.

"Catch and Release"
After breaking into the Beach House and abducting Steven, Peridot brings him to the Galaxy Warp so that he can attempt to use his healing powers to fix it. When he is unsuccessful, Peridot begins to panic about being trapped on Earth and begins to tell Steven about something dangerous about to transpire on the planet. However, before she can give him any details, the Crystal Gems show up and successfully poof and bubble Peridot. Amethyst then proceeds to toss the remaining limb enhancers into the surrounding ocean.

"It Could've Been Great"
Schematics for the Galaxy Warp are seen on the Moon Base computer display.

"Same Old World"
When Lapis is telling her backstory for why she was stuck on Earth, she states that, "It soon became clear there was no hope in stopping the rebellion", and we see the Homeworld warp being used which is at the Galaxy warp.

Trivia

 * In "Winter Forecast", Pearl mentions that Homeworld Gems are able to reach Earth without using the Galaxy Warp, such as by traveling in a Gem Warship.
 * Rebecca Sugar first hinted that the Crystal Gems were intergalactic at the first standalone Steven Universe panel at San Diego Comic Con.
 * It has a crop circle symbol pattern that appears occasionally in the series.
 * This pattern also can be seen aside the left stairs in the entrance of the Ancient Sky Arena.
 * The Galaxy Warp's design resembles circular Gallifreyan, the language of the Time Lords in Doctor Who, who also used to travel across the universe.
 * In an alternate timeline, seen using Garnet's future vision, Steven interrupts the warping process and the Shooting Star detonates, destroying the Crystal Temple.
 * All Warp Pads at the Galaxy Warp are heavily damaged (and thus rendered inactive), the most severely damaged being the Homeworld Warp as of "Friend Ship".
 * The domestic Warp Pad is the only currently functioning Warp Pad at the site.
 * As of "Catch and Release", Peridot has reassembled most of the pieces of the Homeworld Warp, (likely with her tractor beam primarily), although without Flask Robonoids she cannot fully repair it. She tried using Steven and his healing abilities to finish reconstructing it, but failed.