Blacks and Whites ' Carnival ( Spanish : Carnaval de Negros y Blancos ) is a carnival in the Colombian city of Pasto and was proclaimed by UNESCO , as one of the Masterpieces of the Oral and Intangible Heritage of Humanity . Blacks and Whites ' Carnival ( Spanish : Carnaval de Negros y Blancos ) , is the largest and most important celebration in southern Colombia , its geographical indication belongs to the city of Pasto ( The Surprise City ) .