Pausanias Description of Greece 2.5.1

[1]
  On the summit of the Acrocorinthus is a temple of Aphrodite. The images are Aphrodite armed, Helius, and Eros with a bow. The spring, which is behind the temple, they say was the gift of Asopus to Sisyphus. The latter knew, so runs the legend, that Zeus had ravished Aegina , the daughter of Asopus, but refused to give information to the seeker before he had a spring given him on the Acrocorinthus. When Asopus granted this request Sisyphus turned informer, and on this account he receives—if anyone believes the story—punishment in Hades. I have heard people say that this spring and Peirene are the same, the water in the city flowing hence under-ground.

[1] As you go up to the summit of the Acrocorinth, there is a shrine [ nāos] of Aphrodite. The statues [ agalmata] there are Aphrodite herself, armed, also Hēlios, also Eros with a bow. The spring [ pēgē], which is behind the shrine [ nāos], they say was the gift of Asopos to Sisyphus, who knew, so they also say, that Zeus had abducted Aegina, the daughter of Asopos, but refused to give information to the seeker before he had some spring-water given him on the Acrocorinth. When Asopos granted this request, Sisyphus turned informer, and because of that he receives—if anyone believes it—punishment in Hādēs. I have heard people say that this spring-water and Peirene are the same, and that the water in the city flows there underground all the way from here.