Nuraghe Santu Antine, also known as 'Sa domo de su re' ('The house of the king') is an ancient megalithic edifice built by the Nuragic Civilization in Torralba, one of the largest in Sardinia. It is located in the centre of the Cabu Abbas plain. The main structure was built around the 19-18th century BC, and the other parts of the nuraghe date back to the 17th–15th century BC. The main tower originally reached a height of 23–24 metres and contains three tholoi chambers on top of each other. The central tower with diameter of 15 metres is 17 metres high. Santu Antine is made of huge basalt blocks. It has three floors. The top floor is now gone. Some 27 meters long corridors built with the corbel arch technique can be observed inside of the Nuraghe, superimposed on two floors, the Nuraghe was provided with three wells.References:
The Odeon of Herodes Atticus is a stone theatre structure located on the southwest slope of the Acropolis of Athens. It was built in 161 AD by the Athenian magnate Herodes Atticus in memory of his wife, Aspasia Annia Regilla. It was originally a steep-sloped theater with a three-story stone front wall and a wooden roof made of expensive cedar of Lebanon timber. It was used as a venue for music concerts with a capacity of 5,000. It lasted intact until it was destroyed and left in ruins by the Heruli in 267 AD.
The audience stands and the orchestra (stage) were restored using Pentelic marble in the 1950s. Since then it has been the main venue of the Athens Festival, which runs from May through October each year, featuring a variety of acclaimed Greek as well as International performances.