Originally Posted by Rambuster
Centurion lounges definately exist. Some time ago I asked the German Centurion service to fax me a list of the lounges (lost the fax meanwhile). They were mainly in the Middle East. The list of lounges posted by the OP looks more accurate.
There is one in Mexico City Airport for Platinum and Centurion Card Holders, it is opposite the Red Carpet Club of United, they also used to be an American Express Lounge at Vienna Airport