Plunge into the coolest underwater attractions Courtesy of Hill + Knowlton Strategies The Vaersenbaai Car Piles rest 90 feet underwater off Curaçao. Cars, cranes and construction equipment were dumped decades ago in an ill-conceived attempt at reef building. By Justin Ocean, Travel + Leisure Instead of navigating overcrowded Pompeii, why not explore another intriguing ancient city - resting just five to 15 feet underwater off Naples. You'll be snorkeling past eerily beautiful mosaic-floored villas at Italy's Parco Archeologico Sommerso di Baia in no time. Slideshow: See where to find the coolest underwater attractions We're just beginning to appreciate the depth of the ocean's wonders, as demonstrated by film director James Cameron's recent seven-mile free fall to the lowest point of the Mariana Trench, roughly 50 times the size of the Grand Canyon. While Cameron's not eager to promote deep-sea tourism, inspired travelers might be surprised by how much we already have to gawk at below the waves. The coolest underwater attractions include ancient ruins, World War II shipwrecks, art, and kitsch - and you don't necessarily need to be a scuba diver to enjoy them. Swimming in Belize's Blue Hole or sidling up to whale sharks make for memorable excursions, but those kinds of natural phenomena and wildlife are a whole other story. Instead, we're highlighting the surprising array of man-made attractions under the sea that don't depend on Mother Nature (unless you count an earthquake or two). Whatever your snorkeling or diving ability, there's something to see off the southern coast of the candy-colored island Curaçao. A submerged tugboat is easy bait for beginners, while the more advanced can dive deeper to reach car piles about 90 feet below the surface. These "40s and "50s models were junked in an ill-conceived attempt at reef building. Where sea life didn't quite flourish, photo-ops do: you, behind the wheel of a rusty Chevy. You don't need to get wet to enjoy Florida's campy Weeki Wachee Mermaid Show, whose synchronized swimmers have been donning fabric tails since 1947. Another kind of artistry is on display at Cancún's Underwater Museum, which opened in November 2010 with hundreds of sunken life-size human figures. Corals are gradually transforming these statues into living reefs to a haunting effect. Google has even turned its attention underwater, partnering in the Catlin Seaview Survey, which maps the ocean floor in the vein of Google Street View. And even if Cameron won't expand the tourist offerings, you can bet Sir Richard Branson will, with (what else?) Virgin Oceanic, testing now. But there's no need to wait. Take the plunge now to explore these cool underwater attractions.