There is this lovely spot South of Dublin in Dun Laoghaire, Forty Foot Bathing Place. I only made it there once before on a gorgeous january sunday, but this time there were some more swimmers. Indeed, MORE, implying that there was indeed someone brave enough to swim here in the middle of winter!
People have been swimming on this spot for some 250 years. It used to be a male only nude bathing spot until a group of female equal rights activists decided it was time to change and took a dive there.