La Piscine Molitor in Paris. Must be the most iconic pool in the world. As shown in Life of Pi. Jonny Weismuller the original Tarzan was a lifeguard here. First pool to see a bikini too. Best of all it is a hotel and you can stay there.
Isfahan - Iran
Hammam-e Ganj Ali Khan (Bathhouse), Kerman, Iran by Mike Gadd, via Flickr