The Mosque of Ahmad Ibn Tulun was completed in 879 AD. More than 1,100 years later, you can still walk through its courtyard, stand under the same long rows of arches and watch sunlight move across walls that have seen Cairo become an entirely different city. That was the part I could not stop thinking about while photographing it. The mosque was originally built for al-Qata’i, the city founded by Ahmad Ibn Tulun. Most of that city disappeared centuries ago. The mosque remained. And when you step inside, something else happens. Cairo suddenly feels further away. The building sits on higher ground, the courtyard opens up and the sky becomes enormous. For a city known for density, noise and visual clutter, Ibn Tulun gives you almost the opposite experience. I wanted the photographs to hold onto that feeling. Not simply what the mosque looks like, but what it feels like to stand inside something that has survived for more than a thousand years. One of the strongest things about Ibn Tulun is not only the architecture. It is the amount of empty space around it. The courtyard opens directly to the sky, and from certain angles there is almost nothing between the architecture and what is above it. I started treating that sky like another material in the photographs. Stone, shadow, plaster, blue. Sometimes the mosque fills the frame. Sometimes it simply gives the sky an edge.