A six-vaulted Hellenistic rounded fortification was installed in Butrint to separate the area going around the lower part of the hill. The fortification of the walls survived two periods of reconstruction, although there is no documentary evidence to prove this. New walls were made of blocks skillfully combined with each other without mortar. Plumb, fist-wide plots were engraved by engineers. Luigi Ugolini suggested that they should guarantee a correct, straight row of blocks; Hammond discussed this and said that they were convenient for downpipes. Whatever it is dictated, the accuracy of the builders is simply amazing. The well-preserved gate - the so-called Lake Gate - is an architectural gem. A simply made high lintel hides the stone pieces supported by eaves. The same technique was used at Lion's Gate. The gates on the north and west sides leading to the western end of the acropolis are much worse preserved. The main entrance - the Tower Gate - located on the south side, provided access to the Asklepius refuge from the Vivari Canal. This was an impressive entrance made of smaller blocks between a round tower on one side and a rectangular tower on the other. The chrome mechanisms in the front of the gate gave security guards the ability to control access through the gate. A wooden gate crowns the beginning and end of the 7 meter long passage that passes between the two towers.