Mermaid Show In Worlds Deepest Pool Y-40 Video of the inauguration ceremony of the worlds deepest pool Y-40 on June 5. Hotel Terme Millepini is a .brVideo of the inauguration ceremony of the worlds deepest pool Y-40 on June 7. Ideator and architect of Y-40: Arch. Emanuele Boaretto Record depth .brVideo of the inauguration ceremony of the worlds deepest pool Y-40 on June 5. Ideator and architect of Y-40: Arch. Emanuele Boaretto Record depth .