Quiz a local on what the most unique structures in town are and they'll probably mention Cairo Tower. It's one of the first things that'll catch your eye when you start exploring.
This modern piece of architecture in Cairo is popular with fellow travelers, so make a spot for it on your travel itinerary. Don't think that's all there is to do here, though. There are plenty more options ready for you to appreciate after Cairo Tower. Egyptian Museum, Khan el-Khalili, and The Hanging Church are nearby.
