Astral Baths

The Astral Baths in the Radiant Citadel are a popular destination for the wealthier residents as well as species native to the Astral Sea, such as the Gith and Astral Elves. Instead of traditional water, the baths are filled with a substance called Phlogiston, which permeates the Astral Sea. Because of its flammable nature, the bathhouse is protected by wards that inhibit fire, similar to those used in Candlekeep. These wards prevent species like Fire Genasi and creatures from the Elemental Plane of Fire from approaching within 500 feet of the baths.
  The Phlogiston used in the baths is not harvested from the Astral Sea; rather, it is created by a group of three Gith artificers who closely guard the formula. Natives of the Astral Sea often find the baths reminiscent of their home, experiencing a sense of euphoria and bliss. Some users of the baths even believe that it possesses rejuvenating properties, although this may seem peculiar in a city where people do not age.