"In the Yatil Mountains south of Perrenland there is rumored to be a magical hoard of unsurpassed value, a treasure of such fame that scores f adventurers have perished in search of it. Find the perilous Lost Caverns of Tsojcanth and you may gain the hidden wealth of the long-dead arch-mage -- if you live!"
There are certain modules that I've been obsessed with for years & S4 The Lost Caverns of Tsojcanth by Gary Gygax is certainly one of them. There's just something about this module that draws me back into it again & again. All of this is from my B/X Advanced Dungeons & Dragons campaign notes & is not based on canon.
There are certain AD&D adventures that haunt my dreams & S4: The Lost Caverns of Tsojcanth by Gary Gygax is one of those. Perhaps it the fact that S4 fits like a puzzle piece into the bowels of WG4 The Forgotten Temple of Tharizdun (1e). Now according to the Drivethrurpg entry on WG4 this was done on purpose which makes perfect sense;