Contemporaneously with this latter portion of the struggle in the Lycus valley, an incident, possibly of supreme importance, was taking place about half a mile to the northward. Of the three ways into the city which Mahomet declared he had opened for his troops, one was to the north of the Adrianople Gate. The walls between this gate and the Palace of Porphyrogenitus were, in construction, like those in the Lycus valley, but the inner Theodosian wall, instead of extending as far as that palace (now known as Tekfour Serai), stopped short about a hundred yards from it. There a short wall at right angles connected it with the second or Outer Wall. In this transverse wall was a postern giving access from the city to the Inner Enclosure or Peribolos. The short Outer Wall north of the transverse wall, having to do duty for the two city walls, had been made exceptionally strong. A small postern gate, partly below the level of the ground and underneath the extremity of the palace,[418] led directly from the city to the Outer Enclosure. This gate was known as the Kerkoporta or Circus Gate.[419] It had been built up and almost forgotten for many years previous to the siege, but when easy access to the Outer Enclosure was deemed necessary, certain old men recalled its existence and it was reopened. As its position caused it to be concealed from persons who were not close to the tower, it may easily have been left undefended for a while during the night under the impression that it would not be noticed.[420] The Outer Wall between the Kerkoporta and the Adrianople Gate had been largely damaged and a breach made which had been stormed unsuccessfully during the night. The Turks had here also, as well as near the Romanus Gate, been able to pass the ditch and take possession of the Outer Enclosure.