Altar of Aphrodite Ourania
From Project Athinai
The sanctuary of Aphrodite Ourania, initially erected around 500 BC, was probably located at the north foot of the Kolonos Agoraios near the entrance of the Agora, not far on the west from the Stoa Poikile. It was probably a simple open-air sanctuary with an altar. The Persians badly damaged the altar in 480 BC but it was repaired around 450 BC when a statue of Aphrodite Ourania, made by Pheidias, was added to the sanctuary.
The altar rested on a platform of purple limestone measuring 5.1 m wide by 2.4 m deep. The altar was made of yellow poros blocks surrounded by white marble orthostates. The base of the orthostate was decorated with a molding and the crown probably with floral patterns.
The exact limits of the sanctuary are not yet known and it is also possible that a small temple was erected around 450 BC to house the statue made by Pheidias.
American School of Classical Studies at Athens; The Athenian Agora: A Guide to the Excavation and Museum, 1990
Travlos, John, Pictorial dictionary of Ancient Athens, Books that matter, New York, 1971, p. 79