Amsterdam is often called the Venice of the North because of the waterways dividing center city into 90 islands. There are about 1,500 bridges crossing the 160 canals. Collectively, the canals (grachten) stretch for 60 miles. They began as the Singel moat in 1480. Three concentric rings followed in the early 17th century. In 1660, Singelgracht (shown here) was added. The name means surround canal. This aptly describes the city’s original outer ring. The crescent-shaped Singelgracht was once lined with walls, ramparts, bastions and other defenses. Amsterdam’s canal network (Grachtengordel) was designated as a UNESCO World Heritage Site in 2010.