Visual geo-localization is the task of recognizing the geographical location where an image was taken by comparing it to a database of geo-tagged images of previously visited places. This is an open topic of research in computer vision, with numerous recent studies that investigate solutions to make these methods more accurate, robust to appearance changes, generalizable and scalable. This thesis proposes to address two emerging problems in visual geo-localization: - the first aim is to perform an extensive survey of the existing methods in the literature for such task, in order to 1) establish a fair and clear evaluation protocol of these methods, which is missing for visual geo-localization, and 2) provide guidelines on the most suitable approach for practical application.