Turn off location services for Camera & Photo will stop any from being added. To get rid of the "Photos" tab bar section, you must have no photos with geo-tag info in your library. You might be able to just delete the photos you already have with geo-tag info. If this isn't possible or practical, you can sync the phone with iPhoto (Mac) on your computer, and delete the geo-tag info from there, and put the photos back. Absolutely no idea how/if this works on Windows, sorry.
Once you have no photos with geo-tag metadata (the Places tab will show you if there are any), restart the Photos app. To do this, from the home screen, double-tap the button, and you will see the icons of the programs that are running. Scroll until you find Photos. Press and hold the icon, the delete badge will appear. Press the icon to exit Photos. Next time you start Photos, you should find that the Places tab bar item has disappeared.
I just tested this to make sure it works, and it does (on iOS6/iPhone 5 anyway).