Sơn Đoòng Cave in Phong Nha-Kẻ Bàng National Park, Vietnam (© Getty Images)

【May 29 2015】On the north-central coast of Vietnam, in Phong Nha-Kẻ Bàng National Park, a place full of incredible sights, lies Sơn Đoòng Cave, the world’s largest known cave. How large? Its biggest chamber alone is over 3 miles long, 660 feet high, and nearly 500 feet wide. Its stalagmites tower up to 230 feet above the cave’s floor.Explore breathtaking Gallery from the HuluTrip homepage over the past 5 years..