Approximately one-quarter mile past the Lisbon arch, under the Millenium Bank on Rua dos Correeiros, is one of Lisbon's most important archeological sites. Between 1991 and 1995, while excavating a new basement, the bank discovered ancient ruins covering more than 2500 years (including the Visigothic, Islamic, Roman, medieval periods, all the way back to the first human habitation of the area in the 5th century B.C.). Encompassing nearly an entire city block, the ruins contained stone foundations, adobe walls, thatched roofs, clay floors, and a central hearth. One of the largest areas uncovered was devoted to salting and the preservation of fish products dating from the first century B.C. up to mid-fifth century A.D. Adjacent to these commercial spaces, some residential sites (which included living quarters and baths) sprang up around the third century A.D. Sometime between the 5th and 9th centuries, the commercial areas appeared to have been abandoned and turned into necropolises. Beginning in the 9th century, the Moors occupied this site and this change is reflected in the ruins, most notably in the form of artisan products (e.g. ceramics). While admission to the site is free, you do have sign up for a timed, guided tour at the front desk. This is definitely a "must see" attraction.
This first level of the excavations displays some of the ancient artifacts unearthed in the ruins...