The Do-24ATT was a 70s technology prototype by Dornier, Germany. The put the 'new' Dornier wing on it (later used in the other Do types IIRC), plus the gear and turboprops to see if there was a market for an undated 24 (It's one of the most seaworthy 'boats ever).
There wasn't, and it cost Dornier too much.
Iren Dornier took the aircraft from the museum, refurbished it and did it out as a luxury a/c inside in the Philippines, where he lives.
He then set off on a round the world trip, in leasurly stages. Check out the (over complex but) fascinating website for the full details.
www.do-24.com