Opened late last year, the elephant swimming pool at Thailand's Khao Kheow Open Zoo is one of the park's most popular attractions. It's one of only a handful of pools around the world which allow visitors to observe elephants underwater as they swim, and the zoo said it's the largest of its kind in the world.

Elephants are excellent swimmers, like all other mammals. They love water and are great divers, and they use their trunk to breathe like a snorkel in deep water.