Matarayah, Cairo, Egypt
The "Heliopolis Obelisk"The only remaining pharonic monument in what was once the ancient capital city. Urban sprawl has obliterated pretty much everything else. The obelisk itself is within a fenced garden area and there are unofficial paths into it. Gates close just before sunset and official methods require prior permission from the Antiquities Authority. But honestly, getting there as the sun is setting and just watching it slowly glide down behind the structure is all you really need to appreciate its awesomeness.
The process of getting through the extremely urban neighborhood that its buried within can be daunting. Its also half the fun. Have some basic Arabic at the ready as most people in this district do not speak English. Combine this visit with the "Virgin Mary Tree"which is relatively close by. Visit the tree first as it can close early when there are no visitors. Plus, that gives you better timing to appreciate the golden glow of the setting sun at the exact location it used to be worshiped at.