The Harbor of Theodosius, constructed in 4. Century, A.D., was located in the area in which Yenikapı Station of Marmaray and Istanbul Railway is located. The excavations towards both stations in Yenikapı had been carried out in an area of approximately 60000 square meter. A few findings of Roman Era had been found just beneath the Byzantine layer. Findings are generally to be dated back to the 2-4. centuries. Apollo figures made of ivory and statutes of women and men made of marble could be samples of above mentioned findings. Likewise, compared to the findings of Byzantine Era, only a few findings of Hellenistic, Classic and Archaic Periods have been located on the ground made of large and small natural stones at the base of the harbor. Oenochoe, jug, kylix, kantharos and plates might be the good samples. A Neolithic settlement, which was one of the oldest settlements in in Historical Peninsula of Istanbul, was unearthed just beneath the base of the harbor in a loamy black base at 6.40 meters below ground level. In this base, wattle-and-daub architecture ruins, graves, pot, jug, stone and tools made of bone had been found. By this settlement, Istanbul’s history has been taken back 8500 years which had already been known as 2700 years.