I don't do one night stands whether I'm single or not.
I suppose if I was the type of person to do it, the place to find guys isn't really what I'd think about, since you could go to these specific places and not find anyone that suits your interest.
It's 'what kind of guy' it would be with and if you find him, be it in those kind of places or not. After all there is our own personal definition of attractive and unattractive people and one night stands are solidly based on attraction and sexual chemistry.
I've had two before with guy friends of mine, but I left before morning. I don't like sleeping in beds that aren't mine. Both times were great, but I don't really like them. 99% of the time I will not sleep with a guy unless I'm dating him.