Based on the Advanced Dungeons & Dragons module Hidden Shrine of Tomoachan by Harold Johnson and Jeff R. Leason, HackMaster's the Hidden Shrine is designed for characters level 4-6.
Excerpted from the back cover:
Your party is lost! You should never have abandoned the ship and struck out into the jungle, but your pursuers were closing on your trail and it seemed the only way. Stumbling onward, your party makes for higher ground ahead. As you cross a ridge, the sun sinks below the horizon and night comes. A full moon rises, sending moonbeams and ghostly shadows flickering through the branches. Ahead in the dense jungle stands a clearing. There is an ancient ruin suddenly visible -- a worn and overgrown pyramid fills the glade, shining in the moonlight, seeming almost brighter than the moon itself. A refuge, perhaps, this pyramid which reminds you much more of a temple than a tomb. You suddenly notice eerie carvings of Lizard-like men on the stone blocks, and you recall the local legend of the Slaz'Steceks.
A HackMaster adventure for 4-8 characters between levels 4-6, the greatly expanded Hidden Shrine offers over 65 separate encounters spread across five rounds. Each round can be played as a separate tournament adventure, or can be used in an ongoing campaign. Unique traps and monsters with an Aztec theme haunt every twist, turn, and dead end of this fantastic adventure. Only the most cunning and resourceful PCs will escape with the treasures of the Slaz'Steceks!