Rheineck Castle was probably built in the 12th century. The sources name the count palatine Otto I of Salm as the founder. After his death, King Konrad III seized his estate and transferred it to his brother-in-law, Count Herman of Stahleck. This endeavour resulted in a bitter fight for the County Palatine of the Rhine - a conflict that culminated in the complete destruction of Rheineck Castle by the troops of the King in 1151. Rheineck Castle was rebuilt by the Archbishopric of Cologne by 1164 at the latest but did not, however, withstand the Palatine War of Succession in the 17th century. The Prussian politician von Bethmann-Hollweg inherited the ruin in 1832 and had the main building reconstructed together with the castle chapel. The latter represents a special feature, with its eight-sided design, which is reminiscent of the Carolingian Octagon of Aachen Cathedral. Today, the Castle is in private ownership and cannot be visited.
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.