Judging by this signpost, Pioneer Courthouse Square is not just the 
center of Portland but also the world.  It's a short walk (54 yards) to 
the local information center, but a long way to tipperary. <br/> This 
sign would make a good game clue. <br/>

By the way, see the arrow to Suzhou? I was <a target=_blank 
href="/2009_11_17_onward-shanghai/2010_04_16-suzhou/">there</a> 
recently.  (Portland and Suzhou are sister cities.)