A Chronology of D&D Sample Dungeons

The Sample Level — Underworld & Wilderness Adventures (1974)

The Wizard's Tomb — Character Archaic (Sep 1975)

Temple of the Frog — Blackmoor Supplement (Dec 1975)

The Dungeons of the Ground Goblins — Games Workshop promotional flier (1977)

The Sample Dungeon (aka the Tower of Zenopus) — D&D Basic rulebook (Jul 1977)

The Legend of Old Jerol — Different Worlds #2 (Apr 1979)

The Adventure in the Dungeon — AD&D Coloring Album (Apr 1979)

The Dungeon of the Fire Opal — Dungeon Master's Guide (Aug 1979)

The Dungeon of Anhara: A Sample Floor Plan and Cross Section — Games Magazine (Sep/Oct 1979)

The Forgotten Tower — Arduin Adventure (1980)

The Haunted Keep — D&D Basic rulebook (1981)

The Shrine of Kollchap — What is Dungeons & Dragons (1982 book by Hohn Butterfield, Philip Parker, and David Honigmann).

Mentzer Sample Dungeon — D&D Basic rulebook (1983)

Zanzer's Dungeon — Classic D&D rulebook (1992)

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Thanks for Joe Nuttall at the Explore: Beneath & Beyond blog for some of the information regarding the specific months that these products were published, which is found in his "Complete Timeline of Early D&D Scenarios", as well as alerting me to the existence of the Legend of Old Jerol!