Borgarfjörð, the 'fjord of the borg', now West Burra Firt, was so named by the Norsemen on account of the borg (broch) or 'Pictish tower', which still stands on the little holm north of West Burra Firth pier, now greatly ruined. The broch dates to the very early 1st century AD and in the 19th century was 'connected with the land by a bridge of large stepping-stones over which the sea flows at full tide.' The diameter is 18 m and the walls are an average of 4.6 m thick. The stone still stands eight or nine courses high in places.
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.