Crystal Temple is the home base of the Crystal Gems. The house portion first appeared in the "Pilot", while the interior rooms of the temple didn't appear until "Together Breakfast". The interior of the bathroom was not revealed until "Catch and Release". It's appears in Steven Universe.
The Crystal Temple is a sacred place where the Crystal Gems live. It is their base from which they plan how to protect humanity. Inside, the Temple itself is composed of several cavernous rooms, all of which are connected through the Crystal Heart and accessed with the Temple Gate.
Built in front of the entrance of the Temple is a beach house which serves as Steven's home. From camera footage in "Lion 3: Straight to Video" and the flashback in "Story for Steven", the beach house was not built until after Greg Universe met Rose Quartz. As seen in the extended version of the theme song, shown at Denver Comic Con 2015, the beach house that surrounds the entrance of the temple was built by Greg around the time when Steven was a toddler. The beach house was built to give Steven a safe home with normal human house rooms and utilities, such as a kitchen, porch, bedroom, bathroom, etc. as he was unable to use his abilities as a Gem yet, and thus Rose's room was inaccessible for a long period of time.
The statue on the face of the Crystal Temple has eight arms; four arms are spread out, and the other four converge around the Temple's entrance on the figure's navel. Of the four spread-out arms, only the top-right arm still has an intact hand and the broken-off remains of the other hands can be seen sticking out of the beach sands in front of the Temple. The statue's remaining hand is currently used to launder Steven's clothes, with a washing machine and dryer installed upon it and a clothesline strung out between the fingers, and can be accessed via the Warp Pad on its palm. The method in which the washing machine gets its power and plumbing is unclear, described only by Garnet as "magic".
The Temple Gate inside the beach house is able to access different places within the Temple. This is shown when Garnet, Amethyst, Pearl, and Steven each open the same gate into different rooms. The way the door opens depends upon the room it is being connected to: for example, Amethyst's door has a curved line of bubbly goo; Pearl's door is a straight vertical line with a circle around the star on the door; and Garnet's door has two lines that split the door into three parts. Only a Crystal Gem that is able to utilize their abilities can open the gateway.
On the Temple Gate, a star with gems corresponds with the members of the Crystal Gems. The pink gem belongs to Rose Quartz, the cream gem belongs to Pearl, the purple gem belongs to Amethyst, the red gem belongs to Ruby, and the blue gem belongs to Sapphire.
As seen in "Story for Steven" prior to the events of the show, the Temple once had a fence surrounding the entire area. The reason for its removal is currently unknown, but it most likely got removed because of Greg Universe having to come and meet Rose. In the same episode, Greg drives through the fence, suggesting this to be the reason for its absence.