Grønsalen or Grønjægers Høj is about 100 metres long and 10 metres wide, which makes it Denmark's largest long barrow and is widely recognised as one of Europe's outstanding ancient monuments. The barrow, rising over a metre above the surrounding area, is encircled by 134 large stones. The grave, at the centre, is covered with earth and contains three burial chambers, two of which are open. It is not known when they were first opened or what was found inside. The long barrow was examined in 1810 by Bishop Münter and was protected by law after that. On the basis of its shape, the barrow has been dated as Neolithic, approximately 3500 BC. The first historical reference to the site was in ca. 1186 when it was called Grónesund.
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.