The famous Herod Atticus Odeon dominates the western end on the south slope of the Acropolis. It was the third Odeon constructed in ancient Athens after the Pericles Odeon on the south slope (fifth century) and the Agrippa’s Odeon in the ancient Agora (15 BC).
The construction of the monument during the second century AD was sponsored by Tiberius Claudius Herod Atticus, renowned offspring of an important Athenian family and a benefactor; he thus acted in remembrance of his wife Regilla, who died in 160 AD.
The exact date of construction is unknown, but it was certainly built sometime after Regilla’s death and 174 AD, when the traveller and geographer Pausanias visited Athens and referred to the monument in great admiration.
The roofed Odeon served mainly musical festivals, and could host up to 5,000 spectators. It was a solid construction, but the masonry was not massive. Both wall surfaces were covered by poros stone blocks, while the interior was filled with quarry faced stones. The semicircular cavea (in Greek koilo, auditorium), 76m in diameter, was hewn out of the rock.
It was divided into two sections (diazomata, landings) by a 1.20m wide corridor; each diazoma numbered 32 rows of seats made of white marble. The upper corridor of the cavea was probably bordered by a gallery. Also semicircular, the orchestra, 19m in diameter, was paved with white marble.
The scene was raised and the scenic wall, preserved up to 28m, extended over three levels. Arched openings decorated the wall’s upper part, while the lower part contained several tristyle prostasis (three-columned projecting porticos) and niches for the placement of statues, a traditional feature in Roman theatres.
The scene was flanked by staircases leading to the upper diazoma. A gallery called metaskenio lined the front of the outer scenic wall. Mosaic floors with geometrical and linear patterns covered the entrances to the staircases and to the metaskenio. The monument was an extremely expensive construction, which is also confirmed by ancient testimonies referring mostly to the cedar wood used for the roof.