The Dark Kingdom Lair at D-Point
Just the look of the place, as it’s shaped as a demon skull in my opinion, it has just a sinister vibe that it sends off. I remember it used to scare me as a child. (Really I’m a coward when it comes to the simplest things.)
Personally, I depicted this secret lair as one of the most horrid because its the one place was outside of Tokyo in isolation AND it wasn’t set up right in front of civilians. Queen Beryl knew what she was doing when she chose the place.