A colonnade is a series of columns, arranged in order, supporting an entablature and often a sloped roof.

The two colonnades on the east and west sides of the Lower Temenos are triple colonnades (3-rows of columns) with a total of 120columns. In each line of the colonnade there were 16, 18, or perhaps as many as 20 columns. Originally the colonnades were thought to be only double, but in 1996, a third stylobate was uncovered. These lead into the East and West Exedrae.

The total preserved length of the Eastern colonnade is some 42m, with an intercolumniation (space between columns) of 2.50m. The stylobates are constructed of large limestone or white sandstone pavers, which are separated by square limestone slabs, which served as the column bases.

The East Colonnade with the East Exedra seen from the air.

The Brown University 1996 team lining up as columns in the East Colonnade.