Don’t forget your cell phone or phone card.

Carry your phone with you, even if you don’t plan to use it. Turn it off and use it only when you want or need to, but do keep it close at hand. It can be a lifesaver when you’re trying to confirm a museum’s hours, directions, or admission; need to make or change a dinner reservation for later in the day; or if you become lost or disoriented. If your cell phone doesn’t work where you’re going, you can rent one or get a prepaid phone card to make calls home.