It was in Spain, Bonzo3, in 1963. I was surprised, because before I ever went to Spain people said to me 'Don't drink the water!' So I didn't, unless it had been made into hot coffee.
Had nobody given those other people that well known bit of advice?
I heard once that medieval guides for pilgrims going to Santiago de Compostella included warnings about the water in Bilbao. (They were right. The effect of the water there could be dire.)
Sorry if I've put anyone off their soup.