i looked at the "All Topics" list and noted that the RS group sort of has preferences. So I did a quick search of Topics. This really, at best, give some rough order of magniturde and not much else because of variations in names and some countries are more known for a particular city and the country name may never come up in the post. But for grins, here are the results (ignore the list numbers, just from the list i copied - by population). Also, there was no date limit on the posts and some might have been more popular 10 years ago than they are today or the opposite.
Italy 67366 / Rome 43741
France 45153 / Paris 47524
Germany 35206
England 14360 / London 31600 / UK 16538
Spain 23365
Switzerland 22891
Ireland 14704
Austria 14574 / Vienna 11258
Netherlands 5353 / Amsterdam 14445
Greece 10638
Czech Republic (Czechia) 4413 / Prague 10291
Hungary 3578 / Budapest 7280
Portugal 6978
Belgium 6857
Croatia 5933
Turkey 5223
Norway 4621
Poland 3302
Russia 3066
Sweden 2628
Denmark 2319
Romania 1454
Bulgaria 1415
Slovakia 1195
Bosnia and Herzegovina 1158
Finland 1039
Ukraine 901
Serbia 684
Belarus 183
Moldova 137
ATLANTIS 70