Natural Rooms/Roofs

It's a large ask but I would love to see a new style of room generation, focusing on a "natural" room.

I would think to best imagine something like a hobbit hole, a mountainside cave or mine, a stronghold built into a cliff or a hidden bandit hideout in a hill. A natural cavern in a cliffside, that has been constructed by man inside of it. It has a natural roof and walls for it's structure, but inside has some fascia or supports (walls for comfort, beams for support etc).

While similar to caves, the big difference between caves however is that this would exist at ground level as more of a "roof style" than the current cave generation which is more pathbuilding.

For example, if your "natural room" is at Level 0, you would have a block of "terrain" covering it, as if you took an underground building and placed it on ground level, and you could shape that terrain into a rocky mountain, a hobbit hill, a burrow etc.

For the purposes of how it would work scaling through levels, I would imagine it'd be that when on LVL 0, that hill goes away as if it were a roof, but if the highest floor of that natural room is LVL0, then at LVL 1 you would simply see the terrain as it exists (in place of a roof, even if that terrain is much higher than the floor you're on).

Having a new type of room generation method for "Natural" rooms to achieve this would open up one of the final challenges in map design, that elusive blend between natural world and man-made structure.

Currently, the only way to achieve this effect is to manually place objects such as rocks etc to "hide" the cave entrance, this can pose other unforeseen issues and some janky looking transitions.

In short, buildings that create a "hill" around them, that exist above ground. Please!