From the introduction:
Ilmarinen the Eternal Hammerer was once widely worshiped by primitive people, whom he taught how to work metal. But once they had his knowledge, his worship was largely forgotten and his temple declined and was of course overrun by monsters.
The Forge of Ilmarinen is a short mostly hack and slash OSR dungeon crawl adventure featuring 15 rooms and 9 combat encounters, with 11 monsters converted from third edition sources.
While primarily intended for first edition and characters 5th to 7th level, it is easily used with any OSR game.
The scenario file typically is distributed with two high-resolution PNG map files - one keyed and one unkeyed.