After entering your location in the "Where are you going?" field, select "Things to Do".
Ranked in these QuestionsQuestion Ranking
Pro High quantity of reviews
Tripadvisor lists tour options for many of the available attractions. Many of the individual tours have lots of recent reviews so you can get a better idea of what the experience will be like.
Pro Good for food/restaurants
Tripadvisor will usually have the not-to-miss restaurants, even if they can end up being touristy. A good yelp equivalent in non-US countries.
Con Lots of sponsored content
Sponsored content such as sightseeing tours and hotels can clutter up the content users are actually searching for.
Con Lack of trust in reviews
There is a lot of incentive for companies to post fake reviews in order to increase their ranking/visibility. Tripadvisor does very little to catch the false reviews, so it's hard to know what's authentic and what isn't.