Old-School Essentials Official Adventure Scenario: The Incandescent Grottoes encounter but you can use it

but you can use it for whatever

Hawkins and The Halls of Arden Vul (2020) by Richard Barton

The setting is being built over multiple volumes

Severed Books is excited to introduce you to the world of Cavers -- mysterious walking caves that players can have as massive mech-like familiars that are also inhabitable

author of Troika

Old-School Essentials Official Adventure Scenario: The Incandescent Grottoes encounter but you can use itOld School Essentials Adventure A bubbling stream cascades into a hole in the earth, leading to a series of underground watercourses and scintillating grottoes. Adventurers who delve within may discover odd mosses and fungi, a ruined temple complex, and the lair of a crystal eating dream dragon. A classic expedition into the Mythic Underworld for characters of 1st to 2nd level. 57 keyed areas, rumour table, loot summary, dungeon background info,