Did you know that you can cast metal structures on the beach? It may sound like a bit more than a sand castle, but it”s doable…if you”re this artist, at least.

In this amazing video, designer and metalworker Max Lamb creates a pewter stool using the beach itself as one of his tools. He filmed the entire process, seen here in time-lapse, showing him create a one-time-use mold from the beach sand.

Lamb chose to create this hexagonal stool on a beach in Caerhays (on the south coast of Cornwall). The location also holds a special significance. It was where Lamb grew up and spent many a childhood summer playing in the sand and sand-casting, as this process is called. Cornwall was also formerly famous for its mining and foundries, and historically used sand-casting as one of its production techniques.

Lamb carves the shape of the stool right into the beach using a gardening stake and a kitchen knife. Behind him, he”s melting down pewter ingots under the board. The metal becomes liquid at 236 degrees Celsius, which takes about 15 minutes.

Here”s the basic hexagonal shape of the stool.

The molten pewter is poured into the mold. Pewter is mostly tin with some copper and antimony added in. The copper makes the metal stronger, and so this stool is capable of holding a human.

As the pewter cools, Lamb chats with some curious onlookers.

When the stool is cool and solid enough, Lamb begins removing the sand.

The metal is cooled further, and excess sand is washed away with water.

Finally, the heating pit and fire are buried. To anyone walking by, it would appear as though this was just a run-of-the-mill sand castle site.

(via Vimeo/Max Lamb)

You can see more of Lamb”s creations on his website. You can also find more of his making-of videos on his Vimeo channel.