I.m. Pei said this quote

At the beginning, I thought the best Islamic work was in Spain - the mosque in Cordoba, the Alhambra in Granada. But as I learned more, my ideas shifted. I traveled to Egypt, and to the Middle East many times.I found the most wonderful examples of Islamic work in Cairo, it turns out. I'd visited mosques there before, but I didn't see them with the same eye as I did this time. They truly said something to me about Islamic architecture.