Crystal Heart

The "Crystal Heart" is the center of the Crystal Temple. The Gem's Rooms surround it. The Crystal Heart is an enormous red structure which is connected to most of the places in the temple. It was introduced in "Together Breakfast" when Steven gripped onto one of the veins and then slid down it. Pearl says that the Heart is connected to the most dangerous parts of the Temple.

Trivia
Crystal Heart
 * When Steven slides down the center vein the middle area is Rose's Room, hinted by the primary tune played in the episode "Rose's Room".
 * The Crystal Heart is seen again briefly in the episode "Secret Team", when Amethyst and Steven are attacking the escaped arms on it's veins.