Thanks to this world map that shows the density of people with the surname Giostra in different countries, you can get an idea not only of the popularity of the surname Giostra in each country but also of the different migrations of people surnamed Giostra.
The quantity of people with the surname Giostra that we can find in each country can help us discern the origin of the surname Giostra, as logic tells us that the place with the most people surnamed Giostra will be the country or area of origin of the surname Giostra.