Saturday fun activity: Where IS this?

     I was reflecting gloomily on this contest yesterday, thinking, "I've never stumped them. Never! Why?" Maybe I'm too soft-hearted; I just can't pull the trigger on something truly obscure. It seems unfair to you. But when I do—that stone surrounded by velvet ropes. Who was going to place that tucked into a corner of the B'hai Temple? I guess you guys were. In fact, the more obscure I think a place is, like this Pegasus wind vane, the quicker people seem to peg it. Though this really should stump you. You can't see it from the street, you have to go there, and it really isn't a public spot, though the public can, under certain circumstances, visit. I stayed there a while, and have gone back to see friends, from time to time. And there we'll draw the veil. Where is this place? The winner gets ... oh heck, let's get rid of the last of the posters, to make way for the new poster, its design, as we speak, winging its way down to Nashville to be set in type by the good folk at Hatch Show Print. Please be sure to post your guesses below.