Played this at a convention early in the summer. It’s such a deep adventure and, unlike a lot of old-school modules, its’ pretty well thought-out. I’d consider giving it a spin again, maybe with DCC.
Cross-section of D&D module B4: The Lost City, written by Tom Moldvay, TSR, 1982. B4 begins as an adventure for low-level characters but includes maps, keys, and notes for the deeper levels, the underground city and caves beyond that can be used as a self-contained campaign setting.