The Hollow was a geographical feature in the Monoloth Fields. It was guarded by the Guardian, a huge metal robot. It was considered a dangerous place, but ousted by Volgram Pass. It was located in Torren IV. There was a Vullard settlement there. Vullards used this space to melt down junk in the core of an active volcano. The work of junk being melted down was efficient, but not the rest of the settlement. There were often Battery Bot revolts which the Vullards called code 11-13. It was built underneath an old Fongoid settlement that resembled gettohs in South America. They chose that location because junk could be collected from the old tin buildings and reforged. Machinery was noisy but Vullards could be seen relaxing at a Vullard bar or standing around watching the machinery. Ratchet had to help them in order to get to Volgram Pass.
The Vullards did like to keep operation away from the prying eyes of the galactic authorities. This was because some junk they worked with could be valuable or an illegal weapon.
- Ratchet & Clank Future: A Crack in Time (first appearance)