[need rock people] is the Yonaguni 'pyramid' actually carved or is it just how sandstone breaks

Genuinely asking, not trying to start the Atlantis thing. Off Yonaguni, southern Ryukyus, divers since '86 keep filming this huge stepped underwater formation. Sharp right angles, flat terraces, looks like a stepped pyramid or a stage. Kimura, who's an actual marine geologist, says man-made, megali……