Pausanias Description of Greece 6.21.2

[2] In place of the old images of the Maid and of Demeter new ones of Pentelic marble were dedicated by Herodes the Athenian.
  In the gymnasium at Olympia it is customary for pentathletes and runners to practise, and in the open has been made a basement of stone. Originally there stood on the basement a trophy to commemorate a victory over the Arcadians. There is also another enclosure, less than this, to the left of the entrance to the gymnasium, and the athletes have their wrestling-schools here. Adjoining the wall of the eastern porch of the gymnasium are the dwellings of the athletes, turned towards the southwest.

[2] In place of the old images of the Maiden and of Demeter, new ones of Pentelic marble were dedicated by Herodes the Athenian. In the gymnasium at Olympia, it is customary for pentathletes and runners to practice, and in the open has been made a basement of stone. Originally, there stood on the basement a trophy to commemorate a victory over the Arcadians. There is also another enclosure, less than this, to the left of the entrance to the gymnasium, and the athletes have their wrestling schools here. Adjoining the wall of the eastern porch of the gymnasium are the dwellings of the athletes, turned towards the southwest.