Pedestrians in Bolivia´s streets. Picture from http://www.bbc.co.uk/news/
Empty of cars, the streets were turned into playgrounds for street artists, performers and exercise instructors.
Cars and buses were taken off the streets of Bolivia as the country held its first "National Day of the Pedestrian".
All motorised vehicles, including public transport, were banned in cities across the country on Sunday.
Bolivia's government says it wants to raise awareness about the environment.
It comes at a time when President Evo Morales' government is facing criticism over plans to build a highway through the Amazon rainforest.
The recent protests against the highway have been an embarrassment for Mr Morales, who is a prominent advocate of indigenous rights and the protection of "Mother Earth".
Two million cars were taken off the streets on Sunday in nine cities, according to officials cited by Reuters news agency.
In Bolivia's main city, La Paz, the BBC's Mattia Cabitza was engulfed by a sea of young people taking part in a marathon, and the usually congested streets were instead occupied by street artists and other performers.