Oslo

Oslo is Norway's capital and most populated city. It is a county as well as a municipality. In 2021, the municipality of Oslo had a population of 698,660 people, while the city's broader urban area had a population of 1,019,513 people in 2019, and the metropolitan area had a population of 1.71 million people in 2010.

Despite having a large number of active businesses, Oslo is one of the few cities in the world that has been able to keep emissions under control in order to retain the highest air quality. Another factor that has contributed to this city's inclusion on this list is its trash management efficiency.

You will see nothing but clean places wherever you go, whether it is in the lush green parks, lovely gardens, the lakeside, or the seaside. All of this is due to great waste disposal and management efforts.

• Country:Norway