Forbidden Lake

The Forbidden Lake was a lake in Valusia. As the name implies, it was forbidden under penalty of death to enter the lake except for the king.

Geography
The Forbidden Lake was located near the Zalgara Mountains in a great lonely forest that is not named. Its waters were blue and placid with tiny forested islands, and a faint shimmering mist rose from the surface. The islands were said to contain temples and shrines not built by human hands, cloaked by the green foliage and used by the Lake-men to perform strange rituals on certain nights of the year.

Flora and Fauna
The bottom of the lake was covered in a solid bed of harmless bioluminescent moss. This "firemoss" gave off a white glow like a carpet of fireflies. The moss bed was littered with the bones and skulls of those who entered the lake and were killed by the more monstrous inhabitants. The waters themselves teemed with strange but equally harmless creatures that may or may not have been a species of fish. They are described in vague terms, having shadowy forms of multicolored light that were difficult to make out as they swam and darted about. The effect of this natural ecology gave the impression of a magical underwater faery realm.

There were also several types of dangerous monsters that served the Lake-men as guardians against human interlopers. These included an octopus-man hybrid that attacked with its tentacles, giant water spiders, a shark-man with four arms and an impaling horn on its snout, and a giant serpent with green and gold scales.

Lake-men
The Lake-men (or Lake-beings) were the rulers of the Forbidden Lake, and their population numbered in the thousands. They were powerful wizards and inhabited a city of black stone in a great cavern beneath the lake. This cavern realm was known as the Enchanted Land and was illuminated by a black light that radiated from the city itself. Another eldritch feature of the Enchanted Land is that time passed more slowly there. An hour spent in that realm was equal to several hours or a day on the surface world.

The Lake-men appeared much like humans, but their forms glimmered with light and shadow, and their eyes were strange and luminous. They were ruled by a king who is not named, who had a noble, bearded face and a majestic bearing. They had extremely long lifespans, having ruled the lake since before the dawn of humanity and throughout the reign of Kull. Nonetheless, they could be slain by conventional means including mortal weapons. Some of their characteristics were similar to those of the Elder Race, but whether or not they belonged to that people is not confirmed in the original stories. It is worth noting however that Saremes, a cat of the Elder Race, once visited the courts of the Lake-men and stayed with them as a guest for a number of centuries.

Thousands of years before the time of Kull, humans tried to invade the Enchanted Land, so the Lake-men retaliated and waged war against them with powerful magic until the invaders begged for peace. The Lake-men granted this, and the invaders imposed a strict "tambu" (taboo) over the Forbidden Lake that made it against Valusian law for anyone but the king to enter those waters. The Lake-men were not evil by nature, but they never forgot the violence that was done against them and did not tolerate the existence of humans in their realm.