In 1572, during the Eighty Year War with the Spaniards, Sea Beggars (Calvinist Dutch nobles) captured Brielle. After this work began on replacing the Medieval town walls with a modern fortress. This process of modernisation and replacement continued until 1713. The fortress ring has nine bastions and five ravelins and was designed by the fortress builders Willem Paen and Menno van Coehoorn. Since 1713 there have been few changes to the fortress, so the defences are some of the most important fortifications remaining in the Netherlands. It is possible to walk all the way around the walls to view them. Besides the walls there are also various buildings in the town centre which once had a military function, such as the Arsenaal, the Infirmerie and the Hoofdwacht (main guardhouse).
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.