Marc Treanor (19 June 1963 – 2 July 2020) was a sand artist living in Dinas, Pembrokeshire.

[2] He was notable for creating intricate patterns on beaches in Cornwall and later in Pembrokeshire, Wales.

[7] The work would then remain on the beach until washed away by the tide.

[3] As a result of their innately fleeting nature and circular forms, Treanor's sand murals have been compared to crop circles.

[4][5] Marc had a son and a daughter and had begun doing sand art to entertain them at the beach.