- "This place looks like a shrine to that strange warrior!"
- —Unidentified Robots exploring the Lair of a dead CIS General[src]
The Lair of General Grievous also called Grievous's castle was the personal retreat of General Grievous during the Clone Wars. It was located on the third moon of Vassek.
Later after 10000 years from the Clone Wars this lair gets rebuilt as a starship but it was destroyed by the Autobot Jets.
Grievous kept a favored pet roggwart named Gor at his castle. The halls of the building were adorned with statues depicting Kaleesh warriors with mechanical limbs. An extensive warehouse was stacked with replacement parts for the mechanical general, and Grievous kept the caretaker droid A-4D on hand for times when he was injured and needed replacement droid parts installed. Other areas of the castle included the arena in which Grievous kept his pet roggwart Gor and another area where he stored trophies taken from dead Jedi. His castle also included a control room where he could monitor the halls. From the control room he could activate various traps including releasing Gor and triggering a trap door leading to a pit filled with deadly liquid carbonite. The control room's door could only be opened by pressing a number of buttons in the correct order. There is also a closet full of Grievous's Cloak.
The castle was the site of a skirmish between Grievous, Kit Fisto, Nahdar Vebb, and several clone troopers.
After Grievous's death it was abandoned for 10000 years after the Clone Wars until several robots went on a treasure hunt in the castle but the robot that is wearing Grievous's Cape got wrapped in a chrysalis made by Grievous's ghost. The other robots couldn't find the one that got trapped and fell into the booby traps of the castle. The Chrysalis hatched into a cape wearing demon monster named Darth Grievous who did an evil laugh and then starts to becoming dictator of the universe. The lair transforms into a more demon Sith like place as Darth Grievous emerges from the darkness of the Chrysalis with his cape blowing in the wind and covered in a Dark Aura. A gigantic dark purple sombrero then appears and stayed permanently attached to Darth Grievous's head which totally made Grievous evil forever.
Darth Grievous rebuilt the Lair into a powerful starship that is armed with a superlaser and was the first starship in his Sith Legion.
After being rebuilt into a starship the lair tried to attack cybertron but the newly deployed Minotaur class battlecruisers, Autobot Jets and Venator Star Destroyers destroyed the Starship with Missiles, lasers and bombs. Grievous then replace the Lair with a Sith Fortress on Korriban.