Solivagant:
I have found more interest in some of the sights which have NOT been reviewed/visited.
I plan to visit Quebrada de Humahuaca (Argentina) in October: hasn't been reviewed yet but well on the tourist trail. Maybe its name isn't too well-known.
Olinda and Salvador de Bahia in Brazil are really common places to visit. That they have 0 reviews is remarkable for sure. On my trip to Brazil I looked into another unreviewed site, Goias, but that's far from anywhere and doesn't sound appealing enough to warrant a separate journey.
Cuba might suffer from the fact that it's difficult to go there for Americans. There are lots of charter flights from the Netherlands (and probably the rest of Europe) however. The unreviewed sites here include 2 national parks, maybe not the first places to go for sun worshippers.
Colombia can be explained from its violent recent past I think. Also not easy to visit from Europe I believe.
joycevs just visited Bolivia, maybe she can explain why she 'missed' Sucre and Noel Kempff Mercado National Park.
And nobody dares to admit that he/she visited Bordeaux or the Cornish Mining sites!