Photographer Alyn Wallace captured these stunning images of rare bioluminescent plankton in the sea at Three Cliffs Bay in Swansea this week.

"I had to pinch myself this morning," he wrote on Facebook. "Last night I meandered through dark woodlands and waded across a crab-infested estuary to get to this spot where bioluminescent plankton were lighting up the shores.

"Every step and splash I made just lit up with an unreal blue glow."