The ancient stadium of Sikyon, which lies to the west of the theater, is one of the most impressive monuments of the ancient city. It preserves its whole track with its eastern end being artificially supported by means of a massive Ð-shaped retaining wall with curved sides in order to better withhold the earth pressure. The stadium has never been excavated and the combined effect of quarrying for stone throughout antiquity and of post-antique erosion along the cavea have altered the configuration of the monument to a degree that the outline of the track and of the cavea can no longer be recognized.
The purpose of the survey of part of the stadium with a gradiometer was precisely to identify the outline of the track by trying to detect the stone channel that usually lined the sides of the stadia from late-Classical times onwards and possibly the stone starting line on one end and any permanent row seats along the lower part of the cavea.
Despite the considerable noise, the magnetic survey over half of the track yielded a very discernible line over a total length of 107 m, which probably corresponds to the line of the stone channel running alongside the track. Two more parallel lines can be made out along the northern part of the cavea and may correspond to the lower rows of seats, but only excavation can prove this. The width of the track is estimated to be some 28 m, which is comparable to the width of the stadium at Nemea (27 m at its widest point) and larger that the width of the stadium at Epidauros (23.50 m). The total length of the track is estimated to some 198 m, which is long enough to accommodate the actual race track (1 stadion long) and approximately 10 m of extra space on both ends.
In addition to the stadium, we have surveyed with the gradiometer two fields, NP132 after invitation by its owner , and SP35. The small width of NP132 (ca. 10 m) was not favorable towards producing meaningful results, yet we do seem to have architectural remains at the northern end of the tract, which are probably related to an E-W street. Survey of SP35 was prompted by the spectacular geophysical results of adjacent fields (SP30 and SP32) and the recent plowing of the field for olive cultivation. Unfortunately, the iron rods used to prop the new trees masked to a large extent the magnetic readings. We managed however to recognize a few linear architectural features related to the inner division of the ancient insula.