Might and Magic I: The Secret of the Inner Sanctum

"The game is set on the world of VARN (Vehicular Astropod Research Nacelle) which features expansive outdoor terrain, castles, caves, underground cities and an Astral Plane. The game centers around six adventurers who are trying to discover the secret of the Inner Sanctum: a kind of "holy grail" quest. " Source: Wikipedia, "Might_and_Magic:_The_Secret_of_the_Inner_Sanctum," available under the CC-BY-SA License.