Lester McLennan, 20, from London, was reported missing to police in November 2024.

Onlookers said children were playing close to the section of rock when it started to crumble.

A group of up to 18 women in Co Wicklow, made up of skilled knitters, sewers and crocheters, started the project in 2019.

Tourists have been wedging coins into cracks in the iconic basalt rock columns of the Giant’s Causeway.

The art installation on Saturday was the third Northern Ireland event for Green Space Dark Skies.