The remains of the Roman town of Regina Turdulorum, found near the municipality of Casas de Reina in Badajoz province, form an extremely interesting ensemble, in a perfect state of preservation, with the forum and a 1st century AD theatre as its most remarkable features.
The Roman theatre was built in the age of the Flavian emperors, could seat one thousand spectators and was operational until the 4th century AD.
Meanwhile Regina's Roman forum preserves the foundations of some houses, civil buildings, porticoes and the odd remnants of paving or Roman road that transport you directly to this period of history. A porticoed templum with a small room dedicated to the worship of the emperor and the imperial house has also been recovered through different excavations, alongside which other buildings must have existed, such as the market and the basilica.
References:The ancient Argos Theater was built in 320 BC. and is located in Argos, Greece against Larissa Hill. Nearby from this site is Agora, Roman Odeon, and the Baths of Argos. The theater is one of the largest architectural developments in Greece and was renovated in ca 120 AD.
The Hellenistic theater at Argos is cut into the hillside of the Larisa, with 90 steps up a steep incline, forming a narrow rectilinear cavea. Among the largest theaters in Greece, it held about 20,000 spectators and is divided by two landings into three horizontal sections. Staircases further divide the cavea into four cunei, corresponding to the tribes of Argos A high wall was erected to prevent unauthorized access into the theatron and may have helped the acoustics, but it is said the sound quality is still very good today.
Around 120 CE, both theaters were renovated in the Roman style.