I would suggest giving it a block or two of elevation for stairs as well so it looks a bit set off from the ground.
Edit: so quartz walls and stone floors?
Yep, def set off the ground on a pedestal (you can see it on the right of the sections). It'll be required to get decent clearance over the low level platforms as well.
Materials will require experimentation. I think smooth stone exterior, with stone brick/slab detailing. quartz/wood/stone slab interior. tbc.
I've got chests full of sandstone, but I don't think it would go anywhere