Why visit
Hagia Irene stands as one of Istanbul’s oldest standing churches, built in the 6th century on the site of an earlier 4th-century structure and spared conversion into a mosque because it served as the Ottoman arsenal.
What to see
Visitors notice the simple basilica plan, the surviving 18th-century Ottoman additions, and the large cross mosaic high in the apse that escaped iconoclastic damage; the acoustics make it a favored classical-music venue in summer.
Plan your visit
The site sits inside the Topkapı Palace outer courtyard, so combine it with a palace visit or Gülhane Park; modest dress is expected and ablution taps are available in the nearby palace complex.
Good to know
Muslim travelers appreciate the historical layering and the fact that the building never functioned as a mosque, giving a clear view of early Christian architecture without prayer-hall restrictions.
