The Isle of Dread

The Isle of Dread is a thing of legend. Some say it is so laden with treasure that the weight nearly sinks it beneath the waves. Others say it is home to a cult of Kraken-worshippers. Still others say it's Aboleth cultists. Some say a mad scientist populated the island with hideous chimeras who now roam it with a life of their own. Others say the island is locked in time, home to primordial titans who would swat a modern adventurer as easily as a fly.
Even less agreed-on is its location. Most hold that it must be somewhere in Oceanus. Of these, no two people point to the same place on a sea chart, and others believe the island is mobile. Besides these theories, many consider the possibility of the isle being a pocket dimension more likely.

Summary

Stories agree the island is, well, dreadful. The coast is mostly sharp, craggy rocks and cliffs with a few gravelly beaches where the rivers have cut through the stone. Dense jungle covers most of the island, interspersed with stifling hot springs and steaming fens. The caves beneath the island offer no reprieve. Similarly hot and humid, it is plagued by steam vents and pits, and more flooded than not.
They say all manner of dangerous and ancient evil thrive on this island, from shipwrecked pirates to man-eating apes. Some even whisper that gigantic, feathered creatures with teeth and claws each as tall as a grown human, with stature as tall as Mystra's own tower roam its jungles, ignorant of the passage of time.
Many claim to have visited the island and escaped, typically the last survivor of their company, having outsmarted whatever powerful creature the teller believes to have controlled the isle.