The Xanathar Deep-Vault Cache

As the final tumblers of the heavy adamantine door click into place, a hiss of escaping pressurized air signals the seal's breach. The massive circular hatch swings open on silent, oiled hinges, revealing a dry, velvet-lined sanctuary that stands in stark contrast to the surrounding silty depths. Bioluminescent fungi clinging to the ceiling pulse with a soft violet light, illuminating a collection of spoils harvested from the surface and the sea floor alike.