The Dornier Do X was a float plane (i.e. takes off and lands in water) from the 1920s. It would carry 100 passengers. Its was the largest, heaviest and most powerful of its generation. It could convert to 66 sleeping berths for night flights. It could cross the Atlantic, flying at under 1600 feet.
Only three were made. None exist now.
I want one. You can build models of it, but the actual planes have all gone.