Cauldron RHO is a HEPHAESTUS facility that manufactures machines for use in terraforming.
The entrance of RHO is a large triangular door, guarded by Watchers and Scrappers. Inside, the Cauldron is a twisted mass of metal walls, machinery, and wires, similar to Cauldron SIGMA. However, RHO has a number of unique machinery operating in the area, such as giant wheel-like devices. Also, RHO will open into natural caverns. The most notable part of RHO is a giant mechanical "heart", which pumps Blaze to unknown locations. The entire Cauldron appears to be the region's primary collection and distribution hub for Blaze. Inside the core area is a Snapmaw being assembled.
the core area contains a Snapmaw being assembled. Once a pillar is overridden, the field drops, and the Snapmaw attacks, accompanied by a Ravager.