The story of the Oak Island Treasure Pit has been written about in numerous books. To date the treasure has not been uncovered, but tantalizing glimpses chests, and bits of gold and china have been uncovered.
The Pit was an elaborately built trap. The original oak platforms, sealed with putty and coconut fiber, acted like a giant cork and held back the water. Anyone who dug below 90 feet broke the hydraulic seal, causing water to fill the pit. Bailing never worked because the pit was connected directly to the ocean. The design was a masterwork of engineering. To this day no one has been able to stop the flow of water into the pit.
Why the traps, unless it protects something......?