Lind had never been sure of the generic description of the place but he had to admit, it really was an inverted mountain. Further, he saw the natural wind and water wear and tear on it so it was once on the surface!
The cavern had a few wrecked buildings but there was nothing else, not even a teleportation array to get into the damned thing. He instead flew up slowly with only his draconic stamina to support him. He did not find any openings or even hidden doors to crack open.
It was perfectly sealed at the lower peak.
He scaled to the wider base at the top but it was just a mountain. Paths and even some dead scrub brush were everywhere. It was almost surreal in how normal it was if not for being upside down and underground!
He also noted it was not Fiend stone at all. It was granite with a mix of a few other stones. Why was everywhere else Fiend stone but the inverted mountain was normal?