Minty Donald, Malú Cayetano and Nick Millar. A walk tracing the course of a river in Madrid that is now hidden under urban development. We will follow its, presumed, course from the confluence with the Rio Manzanares to where it rises in Vista Alegre. It will take us through, parks, over roads along urban streets and through housing estates. It starts at the Rio Mazanares where a large pipe allows the Pardolongo stream/arroyo to flow into the rio Manzanares. It is surrounded by trees in a park and opposite is a Water treatment plant.