The Undara Volcanic National Park is a protected area located in the Shire of Etheridge, Queensland, Australia. It is found 275 kilometers (171 miles) southwest of Cairns, near the Gulf Developmental Road. The park was created in 2009 to preserve Australia’s longest lava tube and the special animals and plants that live there. The basalt rocks in the area are part of the Cenozoic McBride Basalt Province. These volcanic rocks are all less than 8 million years old, with the youngest rocks being only 7,000 years old.

Location

The Undara Volcanic National Park is located 437 kilometres (272 miles) northwest of Townsville and 275 kilometres (171 miles) southwest of Cairns, two important cities in North Queensland. The park is about 58 kilometres (36 miles) by road from the small town of Mount Surprise. The park covers an area of approximately 61,500 hectares (152,000 acres). The climate is monsoonal, meaning it is usually hot and humid. It often rains heavily from October to late March, while the drier and cooler months are April to August.

The Queensland Department of Environment and Science says much of the park is dangerous for visitors who go without a guide. This is because of hidden holes where lava tubes have collapsed, high levels of carbon dioxide in some tubes, and a confusing landscape. For safety, visitors must be accompanied by a guide to explore the lava tubes. However, the Kalkani Crater can be visited without a guide.

History

Undara is an Aboriginal word that means "a long way." The Ewamian (pronounced your-amin) Aboriginal people are the traditional owners of the national park.

European people arrived in the area in the 1860s. Before the national park was created, the land was used for raising cattle. The lava tubes in the area were known by 1891, and people visited them occasionally, but these visits were not regularly managed. Guided tours began in 1989.

Before the national park was formed, the land belonged to the Collins Family, who moved to the region in 1862. The family built structures, now called the Undara Experience, before the park was created. They were given a special agreement to continue operating for visitors after the park was established.

In 2009, as part of the Q150 celebrations, the Undara Volcanic National Park was named one of the Q150 Icons of Queensland for its role as a "Natural attraction." The park's management plan focuses on protecting the area's geological features and improving services and facilities for visitors.

Geology

The Undara Volcanic National Park is located in the McBride Basalt (Volcanic) Province, which is one of 11 separate Cenozoic volcanic areas in northern Queensland. The McBride Basalt Province covers an area of about 5,500 square kilometers (2,100 square miles).

Within the McBride Basalt Province, 164 eruption centers, including volcanoes, vents, and cones, have been identified. Older lava flows, dated to about 8 million years old, are found outside the national park. Most lava flows are less than 8 million years old. Volcanic activity that created the lava tubes occurred roughly 190,000 years ago. The Undara volcano released large amounts of lava onto the nearby Atherton Tableland, covering an area of approximately 1,550 square kilometers. It is estimated that over 23 billion cubic meters (810 × 10⁹ cubic feet) of lava was released during this event.

A hard crust forms on top of flowing lava, which helps retain heat and allows lava to travel long distances. The longest lava flow in Undara is about 160 kilometers (99 miles) long, with an average slope of 0.3 degrees. Lava tubes extend up to 30 kilometers (19 miles) from the Undara Crater. In some caves, up to five layers of lava flow, separated by smooth Pahoehoe surfaces, have been found.

Bayliss Cave is the remains of a lava tube that was once more than 100 kilometers (62 miles) long. The cave is over 1,300 meters (4,265 feet) long, 11 meters (36 feet) high, and 22 meters (72 feet) wide. It is called a "bad air cave" because carbon dioxide levels inside have been measured as high as 5.9%.

Fauna and flora

The Queensland Department of Environment and Science has identified more than 120 bird species in the area, including the vulnerable Red Goshawk. E-bird has recorded 132 bird species at Undara Experience, which is located near the northern edge of the park.

Undara Volcanic National Park is home to four types of insect-eating bats: the Bent-wing Bat, the Eastern Cave Bat, the Northern Horseshoe Bat (also known as the Eastern Horseshoe Bat), and the Coastal Sheath-tailed Bat. These bats help feed snakes and birds of prey, such as barking owls. Bayllis Cave is one of the world’s most biologically diverse caves. It has recorded 52 species that live there permanently, including the most varied group of arthropods found in a cave in north Queensland.

The national park also has many types of macroropods, which are large marsupials. These include the Common Wallaroo, the Antilopine Wallaroo, and the Northern Quoll.

Much of the park is covered in dry savanna woodland, but lava tubes and areas where the ground has collapsed create wetter conditions that support different types of plants. These lava tubes are covered in thick green vines that resemble plants from the ancient supercontinent Gondwana. A rare white-flowered onion vine grows in these vine thickets within the park.

Gallery

• A view from Archway Cave, looking outward.
• A view from Archway Cave, looking outward.
• From the rim of Kalkani Crater, a view shows Undara Crater in the distance. A line of pale vegetation follows the path of a lava tube.
• From the rim of Kalkani Crater, a view shows Silent Hill, a shield volcano, in the distance.
• From the rim of Kalkani Crater, a view shows Rangaranga Hill, a scoria cone, in the distance.