iMapBuilder for Windows has a placement tool which helps you to pinpoint major cities on the map, please refer:
Add placemarks to locate major cities on an interactive mapIf you are using a Long/Lat supported map template, you can also
add a city, by using its long/lat valuesAlternatively, you can consider to use
iMapBuilder Online, which comes with a [Custom Google Map] option. You can easily pin locations by using country names, city names, street address, or zip code / postcode number.