From the Wikipedia page 
The Notting Hill Carnival is an annual event that since 1965 has taken place on the streets of Notting Hill, Royal Borough of Kensington and Chelsea, each August, over two days (the August bank holiday Monday and the day beforehand). It is led by members of the West Indian community, particularly the Trinidadian and Tobagonian British population or "Trinis", many of whom have lived in the area since the 1950s. The carnival has attracted around one million people in the past years, making it the second largest street festival in the world after the Rio Carnival held in Brazil.
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