Question about Guild Wars Auction house

Here goes one Question about Guild Wars Auction house. How many Auction Houses are there for real? I was thinking there are at least two and then something happened that made me believe that there are more then two, but less then five. I am still confused about this number, can you help me out?

There is just one Auction House as far as I know, and I think that I know a lot about this game. I am sure there is just one and there is no way that the actual number of Auction Houses is between three and five. I don't know what you have been playing but Guild Wars don't have that many Auction Houses. I am really interested in what facts made you believe that there is more then one Auction House. Maybe you will be so kind to elaborate your question a bit deeper. I would really want to find out about this some more, and see if maybe I was wrong the whole time.