Volcanoes can be active, dormant, or extinct. Active volcanoes have erupted recently and may erupt again, like Kilauea in Hawaii. Dormant volcanoes are sleeping but still dangerous as they can awaken and erupt. Extinct volcanoes are thought unable to erupt again, but some dormant volcanoes were once considered extinct. While most active volcanoes are on land, about two-thirds are underwater. Countries with many active volcanoes include Indonesia, Japan, and the United States.