The first gate. Gates are named after the next city one can reach leaving the city from a particular gate. I could not find a name of this one.
The wall in Hellenistic times originally enclosed a square and had a total length of 2839 meters. Later it was extended into a polygon, with a total length of 4420 meters. The oldest part is from the times of Hadrian, most of the main wall dates from the third century. It has been constantly extended and repaired.