@Soretna , I wonder how deep that sinkhole is ?? Could it go all the way to the Hollow interior ?
Allow me to brainstorm ... a giant UFO cut out that perfectly circular hole overnight.
It does look perfectly circular, and Mother Nature doesn't make anything pefectly circular.
And what if it were cut "out" from a cavern world below? Not from above ...
It does say:
"... some 32 meters (104 feet) across and twice as deep..."
So it's roughly 200 (or 208 if precise) feet deep: