Built by Vauban between 1667 and 1672, the purpose of Citadel of Arras was to protect the city from the attacks (Spanish troops coming from the Netherlands). It has been nicknamed La belle inutile (the beautiful useless one) by residents as it has never been directly involved in heavy fighting and didn't keep the Germans form occupying the city in either Word War. Since 7 July 2008 it is part of the UNESCO World Heritage Sites Fortifications of Vauban which includes eleven other fortifications. Within the citadel on the side of La Place de Manœuvre a small Baroque-style chapel was built. Outside, Le Mur des Fusillés (the wall of the people executed by a firing squad) pays tribute to the 218 members of the French Resistance shot in the citadel's ditch during World War II.
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.