The AD&D Module C1: The Hidden Shrine of Tamoachan is a stange mix of tournament-rules and exotic Meso-American aesthetics. Your group's focus is not to beat the dungeon, nor even clear the jungle, but rather to survive and possibly escape. It's a radical departure from the usual stuff that was coming out around the same time as it (1979: Origins, 1980: Main Release). Tamoachan is a tough, demanding module to run. It's even tougher to play in.
"...the whole dungeon is trap-o-palooza, and it’s really important to listen, pay attention, and always assume that when something looks too good to be true, you’re probably dead already, so go ahead and grab it."This was also one of the first modules that included a complete booklet of artwork for the DM to show the players what they were seeing at crucial locations, usually fiendish traps. It was quickly understood that if the DM was showing you a pretty picture, you were in a world of hurt. And to be fair, you usually were, too.
Ken Denmead, Wired: Top 10 D&D Modules I Found in Storage This Weekend
The thing that always made this one module really stick out was not the lethality of the traps, nor even the (then) new monsters, nor even the tournament-style stuff, it was the notion of adapting this module as the entry-point to a whole new campaign in a Central/South American style environment confronting cultures inspired by the Mayans, Incans, Aztecs, and others. That made it really stand out over and above everything else in 1980 and has guaranteed this module a place of honor amongst many, many gamers, game designers, and game developers.
The new series for Cold Text Files begins with PartOne, which lays down the ground rules (better look up 'Atttrition,' 'teamwork, and 'survival,' if haven't already). Part Two sets the stage nicely, especially in terms of some ideas for how to flesh this module out past the core presented in the text itself. Part Three is a very nice explanation of 'paths' and how to map-out a module/adventure into a flowchart...which is really, really quite effective and useful for unraveling the structure of this module--and darned essential for developing something similar for yourself as well. Part Three is very worth your time to read, if you intend to produce adventures or run adventures for actual players.
As this series continues, it should get even more interesting and engrossing as possibilities and opportunities for really fleshing things out pop up around just about every corner of the thing. Grendelwulf over at the Axe & Hammer has also written-up a nice introduction to the Cold Text Files that's worth a look. It's good stuff. Check it out for yourself.