Out with a bang on our final day in Istanbul. We walked our familiar route down the Galata Hill and across the bridge, where we managed to get hustled by two guys cleaning shoes. Then through the wooded park around Topkapi Palace. Such a relief to finally have quiet and shade.

Out the other side and a few more blocks uphill until we stood outside the Hagia Sophia. For such a huge building, it sneaks up on you. From many points down the hill in the old city it isn’t even visible. But standing in line in the large plaza that fronts it, the building’s mass is overwhelming.

Thousands of other tourists approached the building. We took off our shoes and entered. The dome, separated from below by a tier of windows, soared above. The low-hanging circular chandeliers, which only light the lowermost twenty feet of the space, heightened the feeling of separation from the ground to the top. The walls, once covered in thirty million Byzantine gold tiles, are now muted and in varying states of decay. Muffled voices. The smell of sock feet. Kids rolling around on the carpet.

A few minutes after we entered, an announcement: Visiting time was ending as the noon prayer approached. Tour groups shuffled out behind their leaders with their long poles and tiny flags. Guards walked around and asked all the women to leave, or to move to the separate women’s area on the side of the mosque. No more than a few dozen non-observant men, myself included, stayed back, sitting respectfully as observers entered the space.

The call to prayer started. Haunting, beautiful, loud. Then periods of silence, with only three sounds: The cries of small children, birds flapping their wings as they flew inside the dome, and the echo of the call to prayer coming from the nearby Blue Mosque. An absolutely transcendent experience.

I went outside and met Anna. She had spent the time on the women’s side. We debriefed over pineapple and watermelon.

Then a short walk to the Blue Mosque. Spectacular too, but in a very different way: Intricate, spotless, elegant.

Our brains and our eyes were fried. We decompressed with tea and ice cream at the Four Seasons. (Great travel hack: When you’re feeling overwhelmed, get a bite at the nicest hotel in town.) We walked west to our third most of the day, Süleymaniye Mosque, which until a few years ago was the biggest in the city. Gorgeous, but really no match for the first two.

The walk home was a little more eventful than we’d intended. We found ourselves in a small neighborhood just a couple blocks downhill of the mosque full of abject poverty. Streets were no longer paved. Vacant lots were piled high with garbage, as small children and chickens picked it over. Buildings were crumbling, entire walls missing. Just as suddenly, we spilled out onto the waterfront and walked across the bridge back to the hotel.