Yellowstone National Park is a nearly 3,500-sq.-mile wilderness recreation area atop a volcanic hot spot. Mostly in Wyoming, the park spreads into parts of Montana and Idaho too. Yellowstone features dramatic canyons, alpine rivers, lush forests, hot springs and gushing geysers, including its most famous, Old Faithful. It's also home to hundreds of animal species, including bears, wolves, bison, elk and antelope.

Virgin Islands National Park occupies the majority of St. John, one of the U.S. Virgin Islands. Many of the beaches are fringed by coral reefs. They include Trunk Bay, backed by forests, and Francis Bay, whose calm waters are home to sea turtles. Annaberg Plantation has the ruins of an 18th-century sugar plantation. Trails through tropical forests lead to the ruins of Reef Bay Sugar Mill, in the south

Grand Canyon National Park, in Arizona, is home to much of the immense Grand Canyon, with its layered bands of red rock revealing millions of years of geological history. Viewpoints include Mather Point, Yavapai Observation Station and architect Mary Colter’s Lookout Studio and her Desert View Watchtower. Lipan Point, with wide views of the canyon and Colorado River, is a popular, especially at sunrise and sunset.  

Serengeti National Park, in northern Tanzania, is known for its massive annual migration of wildebeest and zebra. Seeking new pasture, the herds move north from their breeding grounds in the grassy southern plains. Many cross the marshy western corridor’s crocodile-infested Grumeti River. Others veer northeast to the Lobo Hills, home to black eagles. Black rhinos inhabit the granite outcrops of the Moru Kopjes.

Denali National Park and Preserve encompasses 6 million acres of Alaska’s interior wilderness. Its centerpiece is 20,310-ft.-high Denali (fka Mount McKinley), North America’s tallest peak. With terrain of tundra, spruce forest and glaciers, the park is home to wildlife including grizzly bears, wolves, moose, caribou and Dall sheep. Popular activities in summer include biking, backpacking, hiking and mountaineering

Galapagos National Park is located about 500 miles (926 km) west of Ecuador, the islands are part of the country. The national park is home to the Galapagos Islands with the park boundaries encompassing an area of 3,040 square miles (7,880 sq km).

There is a total of 21 islands with 18 of them considered significant. The total Galapagos Islands measures square miles (7,995.4 sq km) and spread across 17,000 square miles (45,000 sq km) of ocean waters. Galapagos National Park is a UNESCO World Heritage Site and the country’s first national park.