Yellowstone National Park

Almost every visitor's itinerary includes the world's most famous geyser. — Fodor's

Although West Thumb is not one of Yellowstone’s prime thermal sites, its 0.5-mile shoreline boardwalk loop (with a shorter inner loop to finish with) passes more than a dozen hot springs. — Lonely Planet

This stunning canyon is 23 miles long, but there is only one trail from rim to base. — Fodor's

This massive log structure from 1904 is an attraction in its own right. Even if you don't spend a night at the Old Faithful Inn, walk through or take the free 45-minute guided tour to admire it. — Fodor's

Artist Point is probably the most famous of the canyon’s viewpoints, offering a long overview of the Lower Falls and canyon. — Lonely Planet