Swimmers are being advised not to swim at Barleycove beach after a number of Portuguese Man O'War were spotted in the area.
The Portuguese Man O'War is known for its painful and sometimes dangerous sting.
Its long tentacles can deliver a painful sting powerful enough to kill fish and even occasionally humans.
They can also sting while beached, so beachgoers in the area for a walk are also advised to proceed with caution.
Cork County Council Beachguards posted warnings about the potential risk on their social media accounts this afternoon.