There are many places online that allow visitors to certain areas of the world, or travelers who have used specific airlines or hotels, to post their reviews of their experience.  Before deciding on your destination and making your reservations, spend a little time reading through these trip reviews and find out from the experiences that other people have had whether you really want to go there or not.  Often a particular attraction will be closed or inaccessible and a reviewer will include this in their review of the destination, by reading this information before you make your reservations you might be saving yourself from going on a vacation that would be a huge disappointment.