I always thought the cap stone that covers the hole down to the crypt was the center point of sandbox. It isn't! I have a version of FoMan123's sandbox stacked, which has the cap stone in place using a default piece. If you delete this piece you won't get it back. The Center of the Sandbox Grid has been marked out with a Large Block. This is a block is not a default piece. The only things i can't get it the cap stone to be completely flat there's a tiny step up from the floor. Sandbox Blocked Hope it's useful to some people.