Amastrianum
Istanbul, Turkey
The Amastrianum (Amastriánum, Medieval ῦ, ta Amastrianoú), also called Forum Amastrianum by modern authors, was a public square (forum) in the city of Constantinople (today's Istanbul). Used also as place for public mutilations and executions, it disappeared completely after the end of the Byzantine Empire.
Square data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).