|Died||1938 (aged 69–70)|
Castagna designed St George's Cathedral, an Ethiopian Orthodox cathedral in Addis Ababa, Ethiopia. It is known for its octagonal shape. It is in the northern part of the city. He built it with the work of Italian prisoners of war who were defeated at the Battle of Adwa in 1896. It is named for Saint George.
- "An Italian in Ethiopia". Australia Music Centre. Retrieved 2016-06-10. CS1 maint: discouraged parameter (link)
- Pearson, Hugh Drummond (2004). Letters from Abyssinia, 1916 and 1917. Tsehai Publishers. p. 13.
- "Addis Ababa". Selamta.net. Retrieved November 1, 2008. CS1 maint: discouraged parameter (link)