Your swimming place of choice, would be where?

I have known people who would only swim in a pool, they did not want to deal with any pollution in a bay, seaweed, seal <ahem> you know what, or anything they might step on like jellyfish, plus they liked the idea of controlled water temp. Others were the opposite, they could not stand pools because of the chlorine. They didn’t want to be in confined an area with splashing kids and those who could not leave the pool quick enough to make it to the bathroom. Some picked a middle ground and go for a lake or river, the river being only a clear running one. Muddy ones like the Mississippi or the Sacramento they did not like. 7 out of 10 times what is the location or venue you choose to go swimming and why there?