Alright, well I can throw a few random ideas at you then.
I don't remember the name of this place but it's a fairly big desert area;
Screenshot by Lightshot
This one is from a higher revision but probably wouldn't be a bad place either;
Screenshot by Lightshot
Was also going to suggest western ardounge, but you stated "ardounge" so I'm assuming it's that, or the whole thing.
Not exactly sure on the size but if the second one was to small, perhaps you could add a bridge or something connecting between those 2 islands and have them as 1 map.
Or if my ideas aren't what your looking for, you can grab/look for some from here if you haven't yet:
Interactive Runescape World Map - RuneScape Bits & Bytes