What leaf-fring'd legend haunts about thy shape
Of deities or mortals, or of both,
In Tempe or the dales of Arcady?
The deities or mortals are the gods and humans represented on the urn.
Both the (Valley of) Tempe and Arcady (Arcadia today) are Greecian regions, where the tale of the urn probably takes place.
To help improve the meaning of these lyrics, visit "Ode on a Grecian Urn" by John Keats and leave a comment on the lyrics box