The city of Istanbul has several historical palaces and religious buildings representing nearly every faith that has made its home here over many centuries. Among the oldest Greek monuments, Maiden's (Leander's) Tower is one of the most important. A Greek general the tower in in the 5th century BCE.
The aqueduct of Valens, from the 4th century CE can be seen on the right of the image. It still stands. Historically aqueducts have played an important role in bringing fresh water to Istanbul, and this one has apparently been in use ever since it was built.