From the introduction:
Legend tells of an apprentice necromancer who foolishly believed dark magics would bend to his untrained whims. The end result was an undead plague, as skeletons swarmed the land with chaos and abandon. Scores of adventurers and heroes fought to purge the menace, and they almost succeeded. Only one region still suffers from the spell - the land now called Skeleton Cove.
For some unknown reason this coastal inlet continues to summon skeletons, no matter how many parties clear its caverns - or go missing in its depths. Eventually, a cleric band installed permanent wards preventing the undead from crossing its boundaries. But that hasn’t prevented young heroes from believing they will be the ones to finally loot and clear the caves under Skeleton Cove...
For 3rd level characters. With lots of skeletons.