From the introduction:
In 1982, TSR published the module named The Lost City with the module code B4. It was written by Tom Moldvay and illustrated by Jim Holloway. This 32-page booklet had an outer folder containing maps. In addition to an extensive dungeon complex, the module provided guidance on expanding and creating additional levels and encounters for the adventure. In 2004, for the 30th anniversary of the Dungeons & Dragons game, Dungeon magazine ranked this module the 28th greatest adventure of all time. This conversion guide allows DMs to run the original module with 5th Edition rules and provides a reference sheet for encounters.
A 20+ hour adventure for 1st– 3rd level characters
Note the original module is required for the use of this conversion product.
This item usually is distributed in a ZIP archive containing both the PDF version and the Libre Office version.