The Cryptoporticus of Reims is is a very well preserved third century AD Roman passageway. At the time, Reims was a Gallo-Roman town known as Durocortorum.
Like other structures of this kind, the Cryptoporticus of Reims was a semi-subterranean arched passageway, the roof of which would have been a walkway. It would have been one of three such passageways surrounding the forum of Durocortorum.
The Cryptoporticus of Reims is an excellent example of this type of Roman architecture, particularly as it is so very well preserved.
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.