Well, they are trying to sell their holidays of course so they aren't going to include anywhere they don't go to - so that excludes potential sites in quite a lot of countries (and Gough Island)!
http://www.theadventuretravelcompany.com/en/plan_trip/adventures/heritage_sites.asp


But, not a bad attempt in my view for what is an impossible choice. I have visited all 10 and, as someone who doesn't particularly enjoy the "Latin" countries of S Europe I am comfortable enough with the exclusion of all sites from Italy, France and Spain (though their Tourist Offices and countrymen might not be too happy)!! - though many (including myself) might find the inclusion of St Petersburg as the only city a bit strange despite its attractions. I wouldn't particularly push for any UK sites in a top 10 (only Stonehenge might be "worth a thought"? Though it does provide an awful "visit experience" - but then that is getting true of many of the sites on this list too!). Also I personally would exclude the Great Barrier Reef - as a totality of course it is unique but when one is "under water" you could be in lots of other places also! Ha Long Bay is probably the next most debatable inclusion.

So, if that Martian arrived which 10 should he (it??) be sent to? No Jerusalem, no Rome..?

view these sites. it may help you.

http://thestar.com.my/news/story.asp?sec=Worldupdates&file=/2008/3/7/worldupdates/200 8-03-07T171401Z_01_NOOTR_RTRMDNC_0_-323532-1

http://www.askmen.com/top_10/travel_200/217_travel_top_ten.html

So the "Number 1 Mens lifestyle Portal" (Only from the USA!!) has taken time off from producing of list of "The World's 99 top women" and had a go at the Worlds top 10 WHS!!
a. Not a single site from Asia other than Jerusalem, but 5 from Europe!
b. The Everglades apparently is up there at number 8 for being "one of the most natural World Heritage Sites in the world" (What about the fact that its water flow is man controlled?)
c. Notre Dame (or should it be at "Noter dayme"?) is cited as being a WHS!! Perhaps many of their readers wouldn't know where "The Banks of the Seine" are!

I think I prefer the above travel company's list for all its faults!
Both seem to agree with the "Pyramids" though - and, surprisingly, St Petersburg

Mind you, another widely reported attempt to come up with a "Top 10 list" by the National Geographic Traveller didn't come up with a very satisfactory list either
see http://www.chron.com/disp/story.mpl/travel/top10/4499529.html
Vezelay, Evora, Guanajuato and Bath?? I don't think so!
But, to be fair, although this has been widely interpreted and reported as a "Top 10 List" it was actually a list of those sites considered to be "high" in "sustainable tourism and destination stewardship". For the fuller story see :-
http://www.nationalgeographic.com/traveler/features/whsrated0611/whsrated.html
(Each site on this link leads to a review of its conservation and visiting status - very interesting both in general and for reference if anyone is thinking of visiting but really relating to a different posting subject than this one!)