Mysterious brittle sand structure on the beach

Mysterious brittle sand structure on the beach

Observation - Mysterious brittle sand structure on the beach - UK and Ireland. Description: Found on Criccieth beach North Wales, these large brittle structures made of sand were both on the sand itself and attached to rocks. They almost reminded me of a wasps nest! Mussels were attached to the same areas - wonder if the two are related? They we

Found on Criccieth beach North Wales, these large brittle structures made of sand were both on the sand itself and attached to rocks. They almost reminded me of a wasps nest! Mussels were attached to the same areas - wonder if the two are related? They were obviously strong enough to withstand the waves but were very brittle and could be crumbled between the fingers. Unlike anything I've ever seen and a complete mystery to me!