The main canals, laid-out in a pattern of concentric half-circles, chronicle the growth of Amsterdam during the 17th century, its Golden Age. They are, as seen from the center outward: Singel, Herengracht, Keizersgracht, and Prinsengracht
The Singelgracht, which became Amsterdam’s outer limit at the time, was dug in 1872 for water management and defense purposes, and is not part of the canal belt. Singel is Old Dutch for ‘encircle.’ It wasn’t until the last quarter of the 19th century that the city expanded beyond the Singelgracht.