three of the canals are mostly for residential development (Herengrachtor ‘’Patricians' Canal’’; Keizersgracht or ‘’Emperor's Canal’’; and Prinsengracht or ‘’Prince's anal’’), and a fourth, outer canal, Singelgracht, for purposes of defense and water anagement.The plan also envisaged interconnecting canals along radii; a set of parallelcanals in the Jordaan quarter (primarily for the transportation of goods, for example, beer); the conversion of an existing, inner perimeter canal (Singel) from a efensive purpose to residential and commercial development; and more than one hundred bridges. The defensive purpose of the Nassau/Stadhouderskade was served by moat and arthen dikes, with gates at transit points but otherwise no masonry superstructures.