Situated on the McBride Volcanic Province, the Undara Volcanic National Park is 40 km east of Mount Surprise, with evidence of volcanic activity from 164 craters. One of the most recent and major eruptions 190,000 years ago produced 23 cubic kilometres of lava, most of which flowed down the western side of the Great Divide. This flow created a geological phenomenon now known as the Undara Lava Tubes. The tubes acted as conduits distributing lava over 100 km from the crater, the longest flow in the world from a single volcano.