Gamleborg, also known as Gamleborg Viking Fortress, was the first fortress on the Danish island of Bornholm. Built around 750 AD, it was the seat of the kings of Bornholm during the Viking age (750–1050) and early Middle Ages (1050–1150). The massive fortress is 264 metres long from north to south and 110 metres wide from east to west, with gates to the north and southwest. Around 1100, significant alterations were made and it was reinforced, but it was abandoned soon afterwards in favour of Lilleborg Castle, roughly 700 metres to the northeast.
The fortress is Bornholm's oldest defence works. Its builder is unknown, but an account of the Baltic Sea travels of Wulfstan of Hedebyin 890 tells us that Bornholm already had its own king at the time. There is, however, firm evidence that the fortress was in use during the reigns of Harald Bluetooth (940–986) and Canute IV (1080–1086). The Gamleborg fort was used as refuge during the tenth century against Viking raids. Gamleborg was abandoned in 1150, the occupants moving to Lilleborg, only 700 metres to the northwest. It is not known why the move was made but it does not appear to have been the result of hostilities. Excavations in the 1950s showed the fortifications originated in the Viking period although there is evidence the site was used as a hideout in the Iron Age. The ruins that can be seen today are mainly the result of reconstruction work completed in about 1100.
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.