The Gate of the Spring, also known as the Pege Gate, Balıklı Kapı, and Silivrikapı, forms one of the southern gates of the Theodosian Walls of Constantinople. Located between the Second Military Gate and the Third Military Gate, it originally occupied a position of both practical and symbolic significance. It lies in the modern suburb of Balıklı, between the heptagonal towers 35 and 36, which were extensively rebuilt in later Byzantine times: its southern tower bears an inscription dated to 1439 commemorating repairs carried out under John VIII Palaiologos. The gate arch was replaced in the Ottoman period. In addition, in 1998, a subterranean basement with the 4th/5th century reliefs and tombs was discovered underneath the gate.

The Second Military Gate of the Theodosian Land Walls of Constantinople is situated between towers 30 and 31 of the formidable double-wall fortifications constructed during the reign of Emperor Theodosius II in the early 5th century. It stands in Sümbül Efendi neighbourhood, between Xylokerkos/Belgrade Gate around 430 meters to the south and Gate of the Spring/Silivrikapı some 300 meters to the north. The neighbourhood itself hides several gems of historical nature which are also described below.