Biome Chasms/Lush Chasms

I think It would be cool if there were large pits, open to the sky, but that reach down really deep, it'm talking super large, as in, the size of a super cave, but completely open to the surface

This chasm would have the vegetation of the surrounding biome, as in, if you found one in a jungle, it would have jungle trees and bushes, If you found one in the desert, it would have cacti and dead bushes, if you found one in a taiga, it would have spruce trees and berry bushes, and if you found one in a swamp, it would have mushrooms, swamp trees, and lakes, and even could have waterfalls

They could also have the lush caves vegetation mixed in.

They would only appear in certain biomes, like jungle, taiga, badlands, desert, snowy plains, swamp, and dark oak forests. And they would have to be pretty rare, as in mushroom islands level or rare.