City passes aren't always a good deal, but they can be a stress-free, easy way to build a sightseeing itinerary if you're in a new, or busy tourist city and need help figuring out what you might want to see. Image from queulat00.
If you're heading to a city that has a ton to do, checking the sites available on a city pass will help you focus your trip, even if you opt against buying the pass and go somewhere else. Most city passes will cover the popular sites, which you can use to either take in must-see spots or help you figure out which sites you should skip because they will probably be crowded. You can also use city passes to discover how to group your sites. For example, the Roma Pass groups together the Colosseum, Roman Forum and Palatine Hill as one "site" because they're so close together. If you were visiting Rome, you could do the same in your own itinerary and save travel time.
City Passes: Good Value or Good Way to Ruin a Visit? [Price of Travel]