Undara Volcanic National Park is traditional country of the Ewamian people and is situated around 300 kilometres south-west of Cairns, Queensland. Undara is home to one of the longest lava tube cave systems in the world (“Undara” means “long way”) and the longest in Australia. A hollow tube was created about 190,000 years ago by a single flow of lava. Surviving segments of the tube form caves and arches, including Mikoshi Cave, featured on the stamp in a photograph by Alan Pryke.
Australia 2017, Undara Lava Tube.
The stamp was issued in the series "Caves".