Well, presumably thrown. Matilda Jones, 7, was on holiday with her family when she found the 4ft sword in Dozmary Pool. Her father had just finished telling her about King Arthur, so finding the sword was very exciting.
According to The Mirror, the lake is presumably the same lake where King Arthur hurled the legendary sword after being mortally wounded in the Battle of Camlann. Matilda was paddling waist-deep at the site in Bodmin Moor, Cornwall, when she discovered the blade.
Paul, Matilda's father, said, "It was a blistering hot day and Matilda asked if we could go for a paddle. She was only waist deep when she said she could see a sword. I told her not to be silly and it was probably a bit of fencing, but when I looked down I realised it was a sword. It was just there laying flat on the bottom of the lake."
He also noted that the sword was the same height as his daughter--exactly 4ft!
The legend of King Arthur says that the king first received the sword Excalibur from the Lady of the Lake in Dozmary Pool. He had to row a boat out to receive the blade. It is only fitting that it was returned there upon his passing.
King Arthur's loyal follower, Beivere, was the one to finally cast it into the lake, where the Lady reached up to receive it.
While some like to think the pool is mystical and bottomless, that theory was proven false multiple times, first in 1859 amd again in 1976, when droughts dried out the body of water.
It is, in fact, quite shallow.
The blade, Paul believes, is only around 30 years old, and it "probably an old film prop."
But honestly, do we really think the Lady of the Lake would just let anyone find Excalibur?