This is Sawn Rocks which is nestled in the Mt Kaputar National Park in Northwest NSW. The forty (40) metre high cliff face is the sheered off remains of a basalt lava flow from the Nandewar Volcano which dominated the area 21 million years ago. When the molten rock within the basalt lava flow cooled slowly and, importantly, evenly, this enabled the individual crystals within the molten rock to align perfectly with each other. While this type of five-sided (pentagonal) ‘organ piping’ is not rare to lava flows it is exceptionally rare to find them so perfectly formed and preserved and is recognised as being one of the best examples of columnar jointing in Australia. The perfect polygonal jointing of Sawn Rocks is attributed to the slow and even cooling of molten rock which erupted from the bowels of the earth some 21 million years ago.