The archaeological investigations of 2006 undertaken in the northeastern part of the ancient city of Apollonia uncovered the remains of a portico, which due to its large size, in comparisons with the two other porticoes of the city, was named as “the large portico”. In sondage 5c, at the northeastern part of the monument, the excavations revealed the foundation corner of the lateral walls, while in sondage 5b was found the first columns of the primary line, including that of the opening row of the portico. The foundations of the columns were square with sides 2 m long; and consisted of 5 long parallelepiped limestone blocks on a base of irregular stone blocks. The foundations of the lateral walls were 1, 6 m wide and of irregular stones. The discovery of three stelae bases along the eastern part of the lateral wall, suggest the existence of a row of stelae placed opposite of the portico wall, facing the eastern entrance of the city.
The layer discovered above the stylobate contained a large number of architectural fragments, probably remains from the destruction of the building, including fluted and unfluted column shafts, frames of columns bases, and a frieze with elongated beads or spirals decoration, which are probably part of a Corinthian capital. Also fragments of marble sculptures were uncovered, including that of a hand holding a pyxis.
Within the northeastern corner of the portico (sondage 5c), below the foundation level, two earlier walls, which formed a rectangular corner of north-south and east-west direction were revealed. Their orientation appears to be the same as that of the insulae discovered in the northern sector of the excavations. It seems that, this part of the quarter, which dates to the later Archaic period, was destroyed to make room to the construction of the large portico in the Hellenistic period.
In the central part of the portico (sondage 6), the excavations exposed a squared structure (with sides 4 m long), consisting of a line of large parallelepiped stones, enclosing a fill of irregular and smaller stones. The structure was probably used as statue bases, placed at the central part of the portico. Column fragments of the Doric order were uncovered in sondage 3a, opened in front of the façade of the portico, which were not aligned in the same direction as those discovered in sondage 5b.