People have been digging up there in Oak Island for centuries now looking for a treasure or treasures. There is no actual evidence of a pirate treasure, Revolutionary War treasure, or a Knights-Templar-on-a-lark treasure.
There is also zero evidence that it’s a hoax perpetrated by interstellar aliens laughing and betting from afar on their lucrative space prank.
Millions of dollars have been spent digging and surveying the island and since 1795, all they have found is evidence of previous digs. There are rumors of carved stones and gold coins that were once found, but they have vanished and may never have actually been there in the first place.
A seriously archaeologist wouldn’t pause a moment over such a contaminated site. Seriously.
The one weird feature, the flood tunnels, may just have been an ancient crazy-person project to accomplish some crazy-person goal, which might have been to perpetuate a bunch of treasure legends and lure goofy diggers in to waste their time, energy and of course, money.
My own theory is that the original “mystery” was simply the business plan of a shovel and bucket maker.
All the seekers have spent plenty of money trying to find something and that’s why it’s called The Money Pit, but it’s not the only Money Pit…
[Disclosure: I have not seen the first season finale of the Curse of Oak Island teevee show, but I fully expect one of the bozo brothers to intone, “Well, at least we may have found something that could be wood down there.”]
Update: This is only an “update” because I just discovered this link to a properly researched dissection of the legends. Joe Nickell did a fabulous job of outlining the way this could all have been caused by natural phenomena: The Secrets of Oak Island, Skeptical Inquirer, March/April 2000.