During the year 2003, in the ancient city of Apollonia, an archaeological excavation was undertaken in order to understand an amphora layer that covered an area of 120 m². This amphora layer was noticed since the year 1950 although their function was not clear at the time. The excavation defined the outline area covered by the amphoras which were expanded to a 21 m of length and 5, 7m of width, parallel to the retaining wall of the portico. Three other lines of amphora were without reaching to the natural rock foundation.
The amphorae are of A1 type and were founded inverted, in regular lines. It was initially considered that this unique discovery represents an “amphorae wall”. Based on its size (the biggest known so far in the ancient Greek world), its homogeneity (the utilization of the same type of amphorae), and the dating (3-th century B.C.), this “amphorae wall” was probably used as a drainage system to protect the portico from the humidity, and the city from the possible deluges.