There was a variety of heavy machinery at the quarry. Some were in every day use.

But there were some older machinery in the less used corners of the mine which reflects the quarry’s 50 years of use. I found these more interesting.

When the rock is blasted it forms nice columns, like these. The Giants Causeway in Northern Ireland have similar basalt columns, but in a seaside setting.

They are surprisingly heavy for their size, and are really hard rocks. These are crushed and used to make super concrete. This is the concrete for really big structures, like the World Square building and Anzac Bridge in Sydney.

We were allowed to take some home, and our columns sit happily in our garden at home.

Looking at the walls of the quarry up close, you notice that the grooves lean this way and that, like someone has sketched it.

The grooves are formed when magma, coming out of the volcano, cools. Hubby the geologist says that the way the grooves lean point to the coolest point. Since the grooves on each layer point in different directions, it tells you that the volcano was active many, many times.

Close up, it looks very beautiful, like artwork.

The kids were pretty enthralled too.