Now let’s start with Valens Aqueduct or today's name Bozdoğan Kemeri. This structure may be the most striking one among others because of its importance for the life, aesthetic value and landscape within the city. The construction of the aqueduct was finished by the emperor Valens in 368 AD then named as Valens Aqueduct (Freely and Çakmak, 34). The aqueduct was nearly one km when completed but now only 625 m survives (Freely and Çakmak, 34). It comes from the direction of Edirnekapı and passes through between the third and fourth hills of the Constantinople (Crow, 279). According to the recent studies, the orientation of the aqueduct was deliberately chosen to achieve the most efficient water delivery (Crow, 279).
One interesting note about the monument is that emperor Valens used the old walls of Chalcedon, today's Kadiköy, for the aqueduct project as a punishment for the people of Chalcedon because they supported his rival (Freely and Çakmak, 34). Moreover, there is still an ongoing examination about the aqueduct's early history because some also state that emperor Hadrian was the person who built the first aqueduct along with the same route and Valens reused that (Bardill, Bayliss and Crow, 13-14). Yet, what is clear that Hadrian did improve the urban infrastructure, especially the water supply of the city. That is why it is believed that there could have been an aqueduct from Hadrian’s time due to the demand of the water supply and Hadrian's ambition for city urbanization (Bardill, Bayliss and Crow, 13). However, the ancient city did not extend to this region during the reign of Hadrian but still, it should have been constructed on the same route to bring water efficiently (Bardill, Bayliss and Crow, 13). What is also clear that, for a long time, Thrace was the source of Constantinople's water system, it starts from Istranca Mountains in Vize region and ends in the city itself (Crow, 272). This point is also one of the spectacular features of the aqueduct since the immense calculation and engineering that the long distance, nearly 250 km, between Istranca Mountains and Constantinople requires.
After Romans, the structure was used by Byzantines, and later by Ottomans until the 19th century (Freely and Çakmak, 34). That is why it has a continuous function and multi-layered cultural heritage in it. It is also significant to know that; the aqueduct is one of the rare examples from the city's early phase. Today, although a small part of the structure stands, it is still possible to observe many elements and sections along with the unique glory. The glory that comes from the multi-layered value of Valens Aqueduct or Bozdoğan Kemeri for the people of the city accumulated throughout the city's unique history from Roman period until today.
