10. Yellowstone National Park, USA
All park roads and facilities are open in the summer, and the weather is ideal for hiking and wildlife viewing. Summer temperatures range from 50°F to 77°, perfect for exploring the park. The summer season also provides various ranger-led programs and activities. Try Geyser watching in the Old Faithful area and other geothermal features. Hike in the Grand Canyon of Yellowstone and see its stunning waterfalls. Look for wildlife such as bison, wolves, elk, and bears in Lamar Valley. Enjoy boating and fishing in Yellowstone Lake, the largest high-elevation lake in North America.