The Citadel Namur is a fortress dates originally from the Roman era, but has been rebuilt several times. Its current form was designed by Menno van Coehoorn, and improved upon by Vauban after the siege of 1692. It has been classified as a Wallonia's Major Heritage site.
The original citadel dates to 937. It achieved its present extent between 1631 and 1675, when the city was under Dutch control. This section was called Terra Nova to distinguish it from the smaller fort built adjacent in 1542 and ensuing years. A variety of subsidiary positions were built in the 18th century. It was disestablished as a military post in 1891, superseded by a new ring of forts around Namur that were calculated to prevent the city from being attacked with artillery. This ring became the Fortified Position of Namur in the 1930s.
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.