In what is now the city of Porto, there is a considerable number of natural springs and water sources that supply wells and fountains, which result of a sanitation and water supply campaign addressed to the population. The old Virtudes Nursery Garden is punctuated with fountains, essential to supply water to the Estate. The Frio river, which ran roughly through this area, sprang in the vicinity of what is currently the Torrinha Street, and disembogued into the Douro river.