The Hidden Temple was an ancient base established by the Jedi Order on the planet of Arkinnea around the Old Republic's middle period. After being neglected for centuries, it deteriorated and was left behind. Following the onset of the Great Jedi Purge, Jedi Master K'Kruhk and a group of younglings rebuilt the temple. It served as a haven for Jedi seeking safety during the Great Jedi Purge for years, becoming a whispered legend among the surviving Jedi scattered across the galaxy.
The Jedi Order constructed the temple on the world of Arkinnea during the Old Republic's mid-era; however, the Order later deserted it, and it fell into disuse. Centuries passed, and the Galactic Republic was dismantled and re-formed into the Galactic Empire, an action that almost obliterated the Jedi Order through the implementation of Order 66. In the wake of the Great Jedi Purge, certain Jedi managed to evade the Empire's wrath, including Jedi Masters Zao and K'Kruhk, a Padawan named Chase Piru, and a group of younglings.
When the Jedi's ship crashed on Arkinnea, they were quickly mistaken for a part of the ever-growing stream of war refugees and placed in camps alongside thousands of other beings. Although the camps were overcrowded and unsanitary, they appeared to be on the path to a better life, until the Jedi discovered that the local security forces did not want refugees on their world. The world was also under observation by Imperials under the command of Officer Teron, doubling the danger for the Jedi. It was soon revealed that the militia, led by Captain Relik, were actually massacring the refugees by throwing them over a canyon where they would fall to their deaths.
Once Relik and the others realized that the Jedi had uncovered their secret, K'Kruhk created a diversion while the rest of the Jedi attempted to escape. Nevertheless, Relik's cohorts hunted down the others until they encountered a native sentient species, the Yunu. The militia members then attacked both groups; Zao deflected their blaster bolts with his lightstaff, then lifted a boulder into the air and held them at bay. They soon evaded the militia, while K'Kruhk encountered the Imperial officer Teron, who confessed that he did not believe the Emperor's lies about the Jedi. He informed the Whiphid that, while his salary was meager, he would endeavor to provide the Jedi with whatever they needed and would return each spring with supplies.
The Jedi, along with their new allies, the Yunu, rebuilt the temple and the surrounding structures, enduring a difficult first winter but thriving afterward. Although Zao vanished while tracking a runaway from the group, over the years the younglings developed into strong padawans under K'Kruhk's guidance, and the Jedi managed to live safely for a long time, a rarity under the Galactic Empire. In time, the temple became the stuff of legends among other Jedi survivors scattered around the galaxy. Decades later, the temple was abandoned once more with the construction of the New Jedi Order.
A second Hidden Temple was secretly built to serve as a refuge for the Jedi during and after the Sith–Imperial War.