City wall plus gate

Here the pomerium - the ditch that served to mark the limits of the town - came up to the feet
of the city walls and of the water gate. Water flowed under the imposing edifice with square towers, and entered the
sanctuary via underground galleries. The function of the gate was mainly symbolic: it was not
intended for use by the pilgrims. They entered the sanctuary through one of the four other gates
leading through the city walls. On their way in, they could admire the quality of the work put into
the construction of the surrounding walls. The rampart measured 1700 m in length and featured 17 round towers,
regularly spaced at 80 m intervals. It served no real protection purpose, but was
designed mainly to contain the sanctuary.