Naming a person after an actual place is a practice that has been used to generate surnames for thousands of years. However, now that most people consider their surname something that is relatively fixed, the practice of taking the name of a town, country, river, mountain,... whatever, is being adopted for first names.
Why? Well there are many great reasons to explain this trend. The most obvious reason is that if you free yourself from only considering those names associated with people, the number of names out there becomes essentially unlimited. Another advantage to this practice is that place names are often genderless; the names could serve for either a girl or boy's name.
Place names are a great way to demonstrate your family heritage: you could select the location from which your ancestors came as the name for your child; or perhaps you merely have a personal attachment to a particular region. All of these a valid reasons to name your child after an actual place.
However, if you are expecting a boy, be cautious of names that end in 'a'. Those A's seem to make names feminine (Georgia, Carolina, Catalina). Also be aware that the name of almost every place or geographical landmark already has a meaning or history underlying it for at least one particular cultural group, so some research may be required with this naming technique.