This place - this strange, ethereal place - is... in the middle of blooming Paris!
Well, almost. It's at La Bastille, where a strange subterannean canal meets the magestic (well, it's ok...) Seine, and they have this weird sorta port-thingy, with boats and weeping autumn trees and the whole caboodle.
You should check it out next time you're here in October / November.
And as a mildly amusing aside, you do realise that la Place de la Bastille is where, on the 14th July, 1789, a somewhat pissed off bunch of locals gathered to start what is now known as "the French Revolution", don't you?
Oh well, now you do. More about that somewhere else on the Paris Set Me Free site but, suffice it to say, the Marquis de Launay, governer of the imposing fortress, ended up with his head on a pike and there's no more fortress no more, no more... there's no more fortress no more!! (Could be a song, couldn't it?)