The town of Castelsardo originates from the castle built in the 12th or 13th century by the Doria family of Genoa. The castle and the village which gradually formed round it where the seat of the Doria's fiefdom in the island called Castel Doria or Castelgenovese, until it was conquered by the Aragonese in the 15th century (1448), and named Castillo Aragonés (Castel Aragonese). Later it became the seat of the bishopric until the Cathedral of Sant’Antonio Abate was built in 1586.
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.