Like many other fountains built in the 12th century, the Osmano Street Fountain is incorporated within a building and has an entrance arch to a room located below street level; access was via a staircase.
It was equipped at the back with a very large cistern that was fed by the Prato Baglioni aqueduct.
This canal, which originated from Colle Aperto and ran all along the north side of the hill to end at the Dolphin fountain in the Borgo di Pignolo, is now dry.