Columbus is a mobile application that lets users explore their surroundings through geotagged photographs, presented to them at the location they were taken. By moving around the physical world, the user unlocks photographs and gets to see and experience them in unison with their location. During two consecutive field trials, we investigated how the application was used and experienced and how photographs and locations are explored together. We found that previous experience with the surroundings people was exploring affected how they experienced the localized content. We report on the system's design and implementation, the trials as well as resulting insights that can be used by other developers of locative media applications.