The Church of St. Anthony of Padua is known as the largest active church in Turkey, even though it is not as grand in size as the famous Hagia Sophia. Located directly along Istiklal Street, one of Istanbul’s busiest avenues, its entrance is set back and partly hidden behind an arched portal and a peaceful courtyard.
This church serves a diverse community and regularly holds Catholic Masses in three languages: Italian, Turkish, and English. Each language is offered on different days throughout the week, welcoming both locals and visitors from around the world.
Source - https://en.wikipedia.org/wiki/Church_of_St._Anthony_of_Padua,_Istanbul