As a Fantasy writer...wow...inspiring. I actually like Bluegoggles idea below about it having been a flying ship and crashed there. Oh the possibilities!! Great great job and thanks for the inspiration!!!!!!!!!
Realistically, there would have had to be a massive geomorphic event (such as the emptying of a deep river valley) for this ship to be resting as it is...or the ship was a flying one. But all that aside, I do enjoy the fantastical nature of "the great discovery". Well done.