In this world map, you can check at a single glance which countries have more people with the surname Sidera. As you can see, it's effortless to notice which countries have a higher number of people carrying the Sidera surname.
The quantity of people with the surname Sidera that we can find in each country can help us discern the origin of the surname Sidera, as logic tells us that the place with the most people surnamed Sidera will be the country or area of origin of the surname Sidera.