The Callanish Stones are an arrangement of standing stones placed in a cruciform pattern with a central stone circle. They were erected in the late Neolithic era, and were a focus for ritual activity during the Bronze Age. Archaeological excavation in the 1980s proved that the main circle was erected 4,500-5,000 years ago, and the chambered tomb a few generations later. The setting has a unique arrangement, with lines of stones radiating in four directions from the ring. It is not fully clear whether the stone alignments were constructed at the same time as the ring, or later. The layout of the site, along with many others across the British Isles, appears to have an association with astronomical events, the precise nature of which cannot be determined.
Numerous other ritual sites lie within a few kilometres. These are mainly more modest rings of standing stones, or single monoliths. The most impressive Cnoc Ceann a' Ghàrraidh and Cnoc Fhillibhir Bheag lie just over a kilometre south-east of the main Calanais ring, and originally consisted of rings of stones at least eight in number.
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.