Pausanias Description of Greece 1.22.4

[4]
  There is but one entry to the Acropolis. It affords no other, being precipitous throughout and having a strong wall. The gateway has a roof of white marble, and down to the present day it is unrivalled for the beauty and size of its stones. Now as to the statues of the horsemen, I cannot tell for certain whether they are the sons of Xenophon or whether they were made merely to beautify the place. On the right of the gateway is a temple of Wingless Victory. From this point the sea is visible, and here it was that, according to legend, Aegeus threw him self down to his death.

[4] There is only one entrance to the Acropolis. It affords no other, being precipitous all around and having a strong wall. The Gateway [ Propulaia / Propylaea] has a roof of white marble, and down to the present day it is unrivalled for the arrangement [ kosmos] and size of its stones. Now as to the likenessess [ eikones] of the horsemen [ hippeis], I cannot tell for certain whether they are the sons of Xenophon or whether they were made merely for their good looks [ euprepeia]. On the right of the Gateway [ Propulaia / Propylaea] is a temple [ nāos] of Wingless Nike. From this point the sea is visible, and here it was, so they say, that Aigeus threw himself down to his death.