A route exploring the perimeter of the Roman wall reveals the ancient remains in places such as the Plaça Ramón Berenguer, Carrer Tapineria and the Plaça Nova. The latter is the former site of one of Barcelona's gates. Two towers from the wall bear witness to the fact that carriages and pedestrians once entered the city through here. On one side, adjoining the Casa de l'Ardiaca, or Archdeacon's House, is a section of a modern replica of one of the city's aqueducts. This marked the beginning of one of the main roads in the Roman colony, the former Cardus, today Carrer del Bisbe, which was bisected by the Decumanus a few metres ahead, now Baixada de la Llibreteria.

The Roman Forum stood at the junction of both roads, and is now the site of the Plaça de Sant Jaume. The imposing remains of four columns from the Temple of Augustus can still be seen on Carrer Paradís, in the premises of the ramblers' association, the Centre Excursionista de Catalunya. Nearby, in the Plaça del Rei, the Museu d'Història de Barcelona showcases the interesting archaeological ensemble of the ancient Roman colony of Barcino. The Plaça Villa de Madrid, which stands outside the walled precinct, contains 70 tombs from the city's ancient necropolis.