Yellowstone National Park

It’s not the most visited but Yellowstone National Park deserves to officially be ranked #1: it was the very first to be designated a National Park, way back in 1872 by President Ulysses S. Grant.

Yellowstone sits atop a dormant volcano and is home to half of the world’s geysers, most notably Old Faithful, which erupts every 2 hours, blasting boiling hot water 100+ feet in the air for several minutes at a time.

There are nearly 3,500 square miles packed within Yellowstone’s borders, attracting visitors to the mountains, lakes, canyons, and rivers that an abundance of wildlife calls home.