The Sky Spire is the location where Pearl, Amethyst, and Steven go to look for the Heaven Beetle in the episode "Giant Woman". Within the episode Pearl, Steven, and Amethyst travel through it looking for the corrupted Heaven Beetle, only to be greeted by the aggressive Big Bird, a corrupted Gem that traps Steven, causing Amethyst and Pearl to form Opal and defeat the Big Bird, leaving the Sky Spire in tact.
The Sky Spire is a spire constructed by Homeworld Gems, free floating in the air around the surrounding mountains with smaller floating rocks leading towards it. It is the former home of the Heaven Beetle, who lived in a tiny modern sized house on a little platform surrounded by water, at the top. A spiral light-gray hallway with orange half oval roof tiles travels around the structure to a dome area.
The Sky Spire is where the Heaven Beetle resides. Steven, Pearl, and Amethyst travel here to collect the beetle, succeeding only after a confrontation with a Big Bird. The Big Bird had swallowed the Heaven Beetle some time before the arrival of the three, and Steven retrieves it while in the Big Bird's stomach. Steven is rescued from the monster's belly by Opal. According to Bismuth, the spires are where the most intelligent Gems think.
Steven, Pearl, and Amethyst travel here to collect the Heaven Beetle at the top of the spire where they are confronted by Big Bird. Opal comes to the rescue when Steven and Steven Jr. (a goat) get eaten by Big Bird, inside whom Steven finds the Heaven Beetle.
Schematics for the Sky Spire are later seen on the Moon Base computer display.