A well on Mount Helicon in Boeotia (see Helicon). Similar to the fountain Aganippe it was created when the hoofs of Pegasus struck the ground. Both fountains impart poetic inspiration on those who drink from their waters1 and hence they are dedicated to the Muses.
The name is derived from the Greek ἵππος, "horse," and κρήνη, "well." Presently the name of the spring is Kryopegadi ("cold fountain").
1. Persius. The Satires: Prologue.