Visitors to Hawaii often have something other than visiting a park on their minds. Yet, this island state offers one of the most unusual national parks in the system: the Hawaii Volcanoes National Park. The park covers nearly 505 mi≤/1350 km≤ and has several distinct ecosystems.
Here, explorers can find the results of over 70 million years of the planet's volcanism, including two live samples. They are part of the famed Ring of Fire - a series of volcanoes, many of them underwater, that lie along the edge of several continents. The world's largest, Mauna Loa, stands 13,677 feet high. The other, Kilauea, is considered one of the world's most active volcanoes.