26363
The fourth and outermost canal is the Singelgracht , which is often not mentioned on maps , because it is a collective name for all canals in the outer ring .
 Singelgracht
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Singelgracht