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 Roman Theatre of Mérida is a construction promoted by the consul Vipsanius Agrippa in the Roman city of Emerita Augusta, capital of Lusitania (current Mérida). It was constructed in the years 16 to 15 BCE. One of the most famous and visited landmarks in Spain, the Roman Theatre of Mérida is regarded as a Spanish cultural icon and was chosen as one of the 12 Treasures of Spain.
The theatre has undergone several renovations, notably at the end of the 1st century or early 2nd century CE (possibly during the reign of Emperor Trajan), when the current facade of the scaenae frons was erected, and another in the time of Constantine I (between 330 and 340), which introduced new decorative-architectural elements and a walkway around the monument. Following the theatre"s abandonment in Late Antiquity, it was slowly covered with earth, with only the upper tiers of seats (summa cavea) remaining visible.