1. A computer-implemented method comprising: receiving, by one or more computing devices, information collected at a particular area; identifying, by the one or more computing devices, one or more features and associated locations from the received information; ranking, by the one or more computing devices, the identified one or more features according to relative uniqueness among the identified one or more features; and generating, by the one or more computing devices, a set of geometry data for locating a mobile device at the particular area based on selected ones of the ranked features and the associated locations.