Located between Via Augusta and the provincial forum, Tarragona's circus was once used to hold horse and chariot races. An elongated structure measuring 325 by 115 metres, its original capacity has been estimated at 30,000 spectators. The complex was built in the 1st century. Unusually, it was located within the city limits and is thus endowed with several atypical architectural features. It is considered one of the best-preserved circuses in the West, although some of the original structure remains hidden under old 19th-century buildings. The Praetorium is a Roman-era tower that once housed the stairs that connected the lower city to the provincial forum by way of the circus, to which it is connected by means of underground passageways. It stands at one of the corners of the vast rectangle of the provincial forum square. In the 12th century, it was transformed into a palace for the monarchs of the Crown of Aragon. It was subsequently used as a prison.

Access to the praetorium and Roman circus shall be via the entrance in Rambla Vella. Visitors should exit via the stairs on the terrace of the Gothic Hall in the Praetorium Tower, towards Plaça del Rei.