The theatre is the best preserved monument of the Sanctuary of Asklepios at Epidaurus. It has a perfectly executed tripartite structure characteristic of Hellenistic period theatres: auditorium, orchestra, and stage building (skene). The orchestra is perfectly circular (19.5 m in diameter), with a floor of beaten earth bounded by a ring stones at its perimeter. An open duct running around the outside of the orchestra collects and drains the rainwater that runs off the auditorium. The auditorium itself nestles perfectly into the natural curve of the northern slope of Mount Kynortio at an incline of about 26 degrees. It consists of two sections separated by a semi-circular aisle: the lower section has 34 rows of benches, and the upper tier, which was added during the second phase of construction, has a further 21. Narrow flights of steps divide the two sections into 12 wedge-shaped segments (cunei). The ground plan of the auditorium covers more than a semi-circle, and is slightly elliptical. There is a solid retaining wall at each end. The rows of benches in the eight central tiers were designed as circular curves centered upon the centre-point of the orchestra, while the pairs of tiers on either side form arcs centered upon a point beyond the centre-point of the orchestra. The theatre seats around 14,000. The elongated stage-building adjoining the orchestra, closing it off end to end on its north side, consisted of two parts. At the front was the raised proscenium, with a façade in the Ionian order and projecting side-walls which faced the orchestra. At the back stood the two-storey stage building. The façade of the second floor bore wide openings, which would have housed paintings (backdrops). Two ramps, one on either side, led up to the level of the proscenium. Ionian pilasters flanking the two gates architecturally linked the stage to the retaining walls of the auditorium. The Epidaurus Ancient Theatre owes its excellent acoustics to its geometrically perfect design. Pausanias visited the Epidaurus Theatre in the mid-2nd century AD, that is to say at least four centuries after the completion of the second phase of construction, and expressed his infinite admiration for its symmetry and beauty. Pausanias credits Polykleitos as the architect of this renowned theatre, and for the circular tholos, or rotunda, at the Sanctuary. It is not clear whether this ancient traveler identifies the architect of these buildings with the great Argive 5th century BC sculptor of the same name (who was not alive at the time the theatre was constructed), and the reference remains as yet unconfirmed by scholars. The present form of the Epidaurus Theatre is the result of successive reconstruction and restoration works (by the site excavator P. Kavvadias, A. Orlandos, and the 1988 Committee for the Conservation of the Monuments of Epidaurus Monuments - in progress).