The stadium of Delphi is one of the best-preserved monuments of its kind. It is situated north-west of the theatre, above the sanctuary of Apollo, in the highest part of the ancient city. It was reached in antiquity, like today, by a path winding up from the theatre's left parodos. The stadium is closely connected to the history of the Pythian games, since this is where the athletic events took place.
The original stadium dates to the fifth century BC, as attested by an inscription in the south terrace wall, and had either wooden seats or no seats at all. The existing seats, made of Parnassus limestone - and not of white marble as mentioned by Pausanias, were built in the second century AD by Herodes Atticus, a wealthy Athenian sophist, together with the triumphal arch which decorated the entrance. The latter is a unique feature in ancient Greek stadiums.
The stadium was built into the natural slope, its north side cut into the rock, its south side artificially supported by a walled terrace. The monumental entrance to the east consisted of a triple arch supported by four pillars, the two middle ones having niches for statues. This is where the judges and athletes of the Pythian games entered the stadium under the acclamations of the audience. Behind the entrance is a rock-cut podium with five steps from an earlier building phase, and the remains of a fountain. The track is length one Roman stade long - that is one hundred and seventy-seven and a half metres, and twenty five and a half metres wide. Both the starting-point (aphesis) and finishing post (terma) had stone sills with cavities for the athlete's feet and for the wooden posts, which separated them. The stadium is hairpin-shaped, with two parallel blocks of seats and a semicircular sphendone at the western end. The seats rise 1.30 metres above ground. On the north side is a rectangular tribune where the judges sat in benches with backs. The north side has twelve tiers of seats, while the south side had only six because of the steep slope; both are divided by staircases. The stadium accommodated five hundred spectators.
Although this monument has been conserved and restored, much of the south terrace wall has subsided and must be reconstructed where the building material remains in situ.