Femtocells are often used to extend the coverage of wireless telecommunication networks, but do not typically incorporate mechanisms that allow their location to be easily ascertained. As described herein, a system may determine the locations of femtocells, based on the locations of user devices that attach to, detach from, handover between, and/or detect the femtocells. A map (such as a three-dimensional map) may be generated based on the determined locations of femtocells. The locations of femtocells may be used, for example, in emergency broadcast situations, in order to ensure that messages are distributed as completely as possible in a given region.