The Caves of Arram Koth by Folderol

Arram Koth is a fabled ancient city somewhere in deep space. Many have searched. Few have found it, and even fewer return.

The caves are unique. There are hot springs inside, filling a range of pools that maintain a constant temperature, and with just enough air flow to form perfect hot tubs and saunas. The cave walls are covered with lichen that emit a warm restful light with fluctuating patterns of colour. There is sound too, from the air currents moving through hollow stalactites.

A universe of naked peoples and creatures float, swim, or just bask on natural rock benches - all in total silence.