1. 24 Hours or Midnight to Midnight
Some City Passes (including Dublin and London) count one day from midnight to midnight. So if you arrive in town in the evening and want to use the included transportation from the airport that will count as your first day. Decide whether you want a City Pass according to when you plan to first activate it.
If the City Pass does not include free use of public transport it is often not worth it. Consider how much public transport actually costs. Free public transport might sound great but if the public transport is dirt cheap then it is not relevant. Another tricky point to do with City Passes and free public transport is the zone issue. City transportation is usually divided into zones. You might be thrilled to have your City Pass with it’s free public transport only to find that the site you dreamed of visiting is in a zone that is not covered by the Pass. If you are in a very walk-able city the free transport is also not relevant. However airport transport is always an expensive part of travel so if that is included it might be worth it.
3. How Much Can You See
Really, be honest, how many bloody museums are you going to visit? Actually sit down and work it out to see if the Pass is more expensive than the entrance fees. Some tricky City Pass sites include lists of attractions as “included” when they are actually free anyway!!
It has happened to me more than once that I have purchased a City Pass online and then had to rearrange my whole day to arrange being at the pick-up point when it is open. Take a look at a map. Where is the pick-up point? How will you get there? And when is it open?