A beachgoer spotted a number of bright blue jellyfish on the sand at Kijkduin on Sunday 13 September.
The animals are likely barrel jellyfish, known in Dutch as bloemkoolkwallen or zeepaddenstoelen.
The barrel jellyfish is the largest species of jellyfish found in the Netherlands, growing up to 60 centimetres across.
The species does not have tentacles, meaning it does not cause skin irritation.

