hl, your first clue that it isn't in Amsterdam is that you're reading the section called "Other Cities :: World". GT is a FKK in Germany not too far from the NL border. Here's a map and info:
http://21orover.com/discus/messages/43/64389.html . To learn more details do a search for "GT" or "Goldentime" and you'll find all sorts of useful reports.
