Everyone fights through the crowds at Hagia Sophia, but Little Hagia Sophia (Küçük Ayasofya Camii) offers the same Byzantine architecture experience in complete peace. Built as the Church of Saints Sergius and Bacchus between 527 and 536 AD, it has similar domes and the same ancient atmosphere.

Located in Sultanahmet area, about 10 minutes walk from the main Hagia Sophia. Free entry, and you can actually sit quietly and appreciate the architecture without being pushed around by tour groups. The acoustics are incredible - you can hear every whisper echo. Remember to dress modestly and bring a scarf for covering if needed.