"The Emperor had a private storehouse. It was where he kept all of his private mementos and souvenirs and odd bits of technology he thought might be useful someday. One of the artificial caverns held a complete cloning facility."
Mount Tantiss was originally the site of an Old Republic fort that was reactivated by Palpatine during the Clone Wars.[3] The storehouse contained objects and both trinkets of unspeakable evil and mementos from the conquests of the Empire. His most private treasures were hidden in a massive labyrinth designed by Garrbo V'Droz in the mountain's bottom chamber.
The mountain and its storehouse were guarded by a Dark Jedi referred to as "the Guardian" until he was (presumably) killed by the insane clone Joruus C'baoth.[1]
The mountain also held the twenty-thousand Spaarti cloning cylinders which were used by Grand AdmiralThrawn to create a crew of clones for his new Katana fleetDreadnaughts, and the schematics for the cloaking devices that he would install on those very same ships and would make their way into much of the Imperial Fleet as time went by.[4]
"This alien was discovered near Mount Tantiss by one of the cleansing teams. He had been digging through the soil in the fault line area and had found six datacards."
After the Thrawn campaign, Wayland joined the New Republic and some Noghri set up their settlement near the mountain. The Myneyrshi were in charge of the protection of the storehouse's ruins.[2]
Mount Tantiss was created by the author Timothy Zahn and first appeared in the 1991 novel Heir to the Empire. The name "Tantiss" was intended by Zahn as a reference to Tantalus, a figure from Greek mythology who abused the privileges of the gods.[5]