Take the short walk from the Kilauea Visitor Center or drive to the Steam Vents on Crater Rim Drive to see where steam from the volcano escapes through the ground in large steam clouds. Across the street is the Sulphur Banks, which oozes a gas that smells like rotten eggs. Young children, infants and pregnant women should avoid this area, due to the high amounts of carbon dioxide, sulfur dioxide and hydrogen sulfide.