The Singel is a canal in Amsterdam which encircled the city in the Middle Ages. It served as a moat around the city until 1585, when Amsterdam expanded beyond the Singel. The canal runs from the IJ bay, near Central Station, to the Muntplein square, where it meets the Amstel river. It is now the inner-most canal in Amsterdam's semicircular ring of canals.
The canal should not be confused with the Singelgracht canal, which became the outer limit of the city during the Dutch Golden Age in the 17th Century.
Other Dutch towns also have ring-shaped canals named Singel.