Is there any way to duplicate an exact location???

Hi-I am using iPhoto '11 (9.4.1) on my MBP running the latest version of ML. I have come across a couple of pictures that for whatever reason is not showing the correction location. Of the 3 pictures I took, 2 are correct and one is not. Is there any way to copy the Places info for the correct ones onto the incorrect Places info on the one picture? I can type in the name of the city but the actual location is just outside the city. I am very, very OCD about this. I couldn't see any way to do it. I took the pictures with my iPhone 4S so I am not sure why 2 out of the 3 are correct and one isn't...... This is the first time I have come across this. Thanks so much for any help! Judy