The Incandescent Grotto
A sunken pool leading to a series of caves. At least part of the complex appears to be a trogolodyte temple, complete with actual trogolodytes. There is a source of moss that allows water breathing, and crystals that have a kind of enthralling effect. Human bandits and kobolds may also lair within, and a mysterious pair of skeletons guard a pair of doors within the complex.
The trogolodytes have found some sort of puzzle box that they cannot open. It has a riddle:
"Mountains might, Armies blight, King's conceit, Nobles meet."
We found a dwarf and a frog prince held captive here by the trogolodytes. The dwarf tragically died in captivity.