The September 1979 issue of Penthouse features this fifteen page pictorial of the depraved disco goings-on at Xenon. The club opened in 1978, and had enough cache to be considered a legit alternative (though not a replacement) to the much more famous Studio 54.
Normally I'd include a scan of the cover, but my copy is water damaged, and in pretty bad shape. In fact, it's headed for the recycling as soon as this is posted. I'm not sure why I have it actually.