Dome

Larger canal bridge for motor traffic; Amsterdam, capital of the Netherlands, has more than one hundred kilometres of canals, about 90 islands and 1,500 bridges. The three main canals, Herengracht, Prinsengracht, and Keizersgracht, dug in the 17th century during the Dutch Golden Age, form concentric belts around the city, known as the Grachtengordel. This was placed on the UNESCO World Heritage list in 2010. A fourth outer canal belt, the Singelgracht was built for purposes of defense and water management. There are also many interconnecting canals along radii of the belts. In addition, the river Amstel flows through the center of the city. Houseboats were once a way to deal with the post-WWII Amsterdam housing shortage, however, nowadays they are in high demand; there are approximately 2,400, with 750 of those in the inner canal ring. They are regulated (by number of licensed mooring places) and since 2005, tied into the city water and sewage systems. Some of the houseboats are converted cargo vessels, others are purpose-built. Source: Wikipedia; http://en.wikipedia.org/wiki/Main_Page (accessed 7/14/2014)