The big island of Hawaii comprises over half of the area of the state of Hawaii in the United States. To avoid confusion with the state, it is almost universally called the Big Island. It is home to the most active volcano in the world, located in Hawaii Volcanoes National Park, as well as the largest mountain in the world in volume (Mauna Loa) and the tallest mountain in the world as measured from its base on the sea floor to its peak (Mauna Kea).
The Big Island has the usual array of sub-tropical island activities. Its beaches, especially on the Kona side, are consistently voted as the best in the world. Some (like Mauna Kea Beach) front hotel resorts, while others (like Makalawena) remained unencumbered by modern tourism. Hapuna Beach is reputed to be one of the best. The island also has one of the few green sand beaches in the world, and several black sand beaches.
The Big Island also has some fantastic snorkeling. The Kona side has most of the best snorkeling, but Puna also has some excellent sites. Go in the morning on the Kona side, and in the afternoon in Puna, for clear and calm conditions. Active visitors may enjoy the Big Island’s surfing, scuba diving, hiking and camping.