Hawaii is comprised of eight isolated volcanic islands in the Pacific Ocean. These islands are actually only the visible parts of a much larger undersea mountain range that stretches 1,500 miles across the Pacific in a northwesterly direction. The entire range is called the Hawaiin chain. Of the visible islands, the "big island" of Hawaii is the one located farthest southeast, and is Hawaii's volcanic center. It is larger than all the other main islands combined, and is comprised of five volcanoes, one extinct, one dormant, and three active. A portion of the island is included within Hawaii Volcanoes National Park. Two volcanoes dominate the island, Mauna Kea (13,796 ft.) and Mauna Loa (13,677 ft.).