The City wall of Visby (Swedish: Visby ringmur) is an old medieval defensive wall surrounding the city. The building of ringwall was probably started in the 13th century. Around 1280 it was rebuilt to reach its current height, along with the addition of its characteristic towers (although some towers were not constructed until the 15th century) It is part of the UNESCO World Heritage Site in Visby. The war in 1288 between the citizens of Visby and the Danish army gave the citizens of Visby a reason to continue the work with the wall. All together the city wall became 3.4 km, and it was finished in the beginning of the 14th century. At the time, the wall contained 29 towers, 27 of which are remaining today.
During the 1361 Battle of Visby, the main battle was fought within 300 meters of the North Gate of Visby (shown on the right). The peasant forces were ultimately unsuccessful, however, resulting in the citizens of Visby surrendering to the Danish forces.
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.