I'm making a unit conversion code to convert from an Earth-Centered, Earth-Fixed (ECEF) location to a Latitude, Longitude, and Altitude (LLA) location and vice versa. I'm also making a code to convert from East, North, Up (ENU) to both of these locations as well. I have the code written out but I don't have any reliable data to test my code. Does anyone know of a link I can go to for the different location units of major cities and the north/south poles? If not a link to a reliable conversion calculator would help as well.