The Capitol dome is the largest dome by volume in the United States and one of the largest in the
world. It is also the only granite dome in the United States. The dome consists of inner and outer
structures. The inner dome (coffer dome) is visible from the Capitol rotunda. Three observation
decks encircle the outer dome. The lowest observation deck is open for public viewing during the
summer months. The dome rises 162 feet above the wings.