Tons of natural swimming holes, known as cenotes ... Each year, the spectacular Havasu Falls attracts thousands of visitors.

At Water Wheel Falls in Payson, Arizona, you'll find a series of swimming holes to cool off on a hot day.

Mule reservations can also be pricey, starting at $200 for one way. Swimming is allowed at Havasu Falls, and a popular activity for travelers who make the trek. The water maintains a pleasant ...