Dividing Yellowstone National Park in two is the Grand Canyon of the Yellowstone. Offering spectacular vistas along its cliffs, the canyon begins at one of the most visited attractions in the park. This is the Lower Falls. At a little over 300 feet tall, it is the largest waterfall in the park. For most of the year, tens of thousands of gallons of water rush over the brink into the canyon below every second awing visitors with the massive power of nature.