I use this to keep track of websites that provide lists to the most important tourist attractions around the world -- which I use for my work. I maintains this more like a webpage and will update it as I find resources to add. Suggestions are welcome.
Lists of theTop Tourist Attractions in the World
1 - Planetware - Attractions listed by country - based on Baedeker Guides, this may be the most complete list of top attractions (4 and 5 star-rated), listed by country, that is available anywhere. From this link, click on a country, then click on Top Attractions. For a more complete list (and alternative attractions) click on the Attractions link.
2 -World Tourist Attraction Guide - A fairly comprehensive list of major world tourist attractions by region. Also includes country information, contact addresses for additional tourist information, videos and photos of some destinations, and maps. Some areas may still be under construction.
4-Sightsmap - A Google Map of the most photographed places on the internet. Zoom in at any scale to see the ten most photographed sites, which are frequently also the ten most popular or visited attractions. Zoom in even more to see actual photos.
Top Specialty and Niche Attractions
1. UNESCO World Heritage List - Even better is The Tentative List (on the sidebar menu of this site), which includes sites that countries plan to propose to the Heritage List in the future, and many of which are "undiscovered" by the mass tourism industry.Also on the sidebar menu is their World Heritage in Danger List.