Fascinated by America’s greatest geological beauties? Take a visit to the US’s third largest lava tube: Ape Cave Lava Tubes! Visitors can explore this beautiful cave just beneath the forest floor of Mount St Helens National Volcanic Monument near Stevenson, Washington. You’ll be able to visit the lower cave in an hour and have beautiful views to take photos of. However, for more adventurous visitors, feel free to stop by the upper cave which will feature even more beautiful sights! Reservations are required to visit the lava tubes and visitors should bring a flashlight in order to best experience the Ape Cave Lava Tubes.