Yes, Seven Seas Lagoon, the massive body of water that guests must cross to reach the Magic Kingdom, is entirely man-made. Completed in 1971, the lagoon was excavated from what was previously a low-lying marshy area. The project was a massive engineering feat: workers moved more than seven million cubic yards of earth to create the basin. Interestingly, the dirt removed from the lagoon was used to build the "utilidors" (utility corridors) and provide the elevated foundation for the Magic Kingdom park itself, which technically sits on the second floor of the resort. The lagoon is approximately 14 feet deep and holds millions of gallons of water. While it looks like a natural Florida lake, every contour of its shoreline and the three islands within it—Blackbeard Island, Castaway Cay, and Beachcomber Island—were strategically designed by Disney Imagineers to serve as a scenic "buffer" between the Transportation and Ticket Center and the fantasy world of the theme park.