AD&D 1e: I7 - BALTRON'S BEACON (1985)

From the back cover:

A strangely delivered advertisement has led you to a sage named Demetrios. He needs a rare component to complete a desperately needed potion. The journey to retrieve it will take you through a large, unexplored swamp to a ruined keep, the former headquarters of a vile cult that once claimed the lives of many innocent youths.

To solve the mysteries of Baltron's Beacon, the characters must excel in handling wilderness, building ruins, traps, puzzles, and new monsters. This adventure, originally designed for tournament use, is now available for your own campaign.

An adventure for 5-10 characters, Levels 4-8.