Said to be large enough to “swallow a boat,” the Lake Texoma vortex seen below is actually the result of intentional draining due to high water levels following Texas’s record rainfall this summer. You wouldn’t need to tell me twice to keep my distance from this monster:
You can read more here. Of course, even this impressive whirlpool has got nothin’ on the famous disappearing Lake Peigneur, a catastrophic vortex which devoured a “drilling platform, eleven barges, many trees and 65 acres (260,000 m2) of the surrounding terrain.”