Abandoned underground silo, open to...

Abandoned underground silo, open top exposed to sky. Massive ancient obelisk-like structure at center on a platform of cracked stone bricks and chiseled stone bricks. Structure built from deepslate, cobbled deepslate, and polished blackstone with mossy stone brick accents. Corroded framework using iron bars, chains, and copper blocks (oxidized/weathered copper for rust look). Collapsed catwalks using cobblestone stairs and stone brick slabs, some sections broken/missing. Walls of cracked stone bricks and mossy cobblestone, covered in vines, moss carpet, and moss blocks. Lush greenery spilling from the open top: vines, hanging vines (weeping/twisting vines work well), ferns, azalea bushes, oak/dark oak saplings and trees rooted in cracks, lily of the valley scattered around edges. Deep vert