Suitable for the more active visitors, this two hour tour involves climbing over rocks and walking on uneven surfaces. The ultimate lava tubes experience. Undara lava tube system is Australia's longest, and one of the longest in the world. The lava tube caves in this national park are the finest examples in Australia and contain specialised ecosystems that are internationally significant. Bayliss Cave is considered one of the world's most important, biologically diverse caves. It contains at least 52 resident species of animals. Other examples of well-preserved volcanic features in the park include craters, lava ponds and flows, and perennial springs. Undara Volcanic National Park, and much of the Etheridge Shire, is regarded as the traditional country of the Ewamian (pronounced yur-amin) Aboriginal people. This tour is not suitable for children under 5 years old.