The Keep on the Borderlands
Gary Gygax
 Player characters begin by arriving at the eponymous keep, and can base themselves there before investigating the series of caverns in the nearby hills teeming with monsters. These Caves of Chaos house multiple species of vicious humanoids. Plot twists include a treacherous priest within the keep, hungry lizardmen in a nearby swamp, and a mad hermit in the wilderness. It typifies the dungeon crawls associated with beginning D&D players, while permitting some limited outdoor adventures. When The Grand Duchy of Karameikos edition of the Gazetteer series was published, the Keep was given a specific location in the Known World of Mystara, in the Atlan Tepe Mountain region in northern Karameikos.