Sharon Luther, age 15, of Shreveport, La., for her question:

WHERE IS THE WORLD'S LARGEST INACTIVE VOLCANO CRATER?

Haleakala Crater on the island of Maui in Hawaii is the world's largest inactive volcano crater. It is about 2,300 feet deep and has a circumference of 21 miles at its rim.

The name has five syllables. Here's how you pronounce it: Haa lee ah kaa la.

Richly colored cinder cones of varying sizes rise from the crater floor. The cones may be reached on foot. Clouds sweep into Haleakala and help supply moisture for the few pockets of vegetation, which include the sandalwood tree, Hawaiian snow (a lichen) and the rare silversword.

Kipahulu Valley, on the volcano's eastern slope, contains a luxuriant tropical landscape.

Haleakala, for centuries revered by Hawaiians as a spiritual center, means "House of the Sun." The remains of an ancient stone roan have been found in the crater.

Haleakala National Park originally was part of Hawaii Volcanoes National Park on Hawaii Island. It became a separate historic location in 1916. In addition to the crater, the park includes Puu Ulaula observatory, a satellite tracking station.