Those cities do not seem to have any problems with junk collection and waste management. Or is it just because they are so ahead of any competition that they seem like they do not need junk collection at all?
1) Freiburg, Germany 
The main reason Freiburg makes the list is the fact that Germans are simply quite into eco-friendly living solutions. That is why this magnificent city, surrounded by green hills, is also one of the greenest in the world.
2) Oslo, Norway
Recycling and environment protection in general is big in the northern countries. This is particularly evident in Norway’s capital, where the laws and regulations about waste management, garbage disposal, air and water pollution are pretty strict – but still, the results are more than evident.
3) Helsinki, Finland
As we have already said, leave it to the Baltic countries to be clean and eco-friendly. Not only the nature in and around Helsinki is wonderful, the place is the center for culture in this part of Europe. The fact that the streets and public places in general here are impeccably clean is yet another reason Helsinki is such a great place.
4) Wellington, New Zealand
Wellington is a comparatively small city that is not particularly popular with tourists. This is probably the reason why it is easy for the local administration to keep it clean and tidy at all times. Yet again, many equally small and unpopular cities cannot much the public hygiene of Wellington.
5) Copenhagen, Denmark
It looks like European capitals are really involved in the efforts of providing their citizens with clean and eco-friendly environment. Copenhagen is a really beautiful place, and it is flawlessly maintained at any time. The rich cultural and historical tradition of the place make it not only one of the cleanest cities in the world, but the most interesting too.
6) Kobe, Japan
The Japanese people are known world-wide for their discipline and aim at perfection. So it is no wonder that a Japanese city is featured in the list of the cleanest urban environments in the world. Kobe is located near Osaka and has a thriving economy. This, in addition to its highly responsible citizens, is most probably the reason why it is also so clean and tidy.
7) Minneapolis, USA
The Water City is very near the top of the charts when it comes to tidiness and clutter-free streets. Trading is the main economical branch here, and as we all very well known, a clean work place is the key to keeping your customers happy. This is likely the reason why Minneapolis looks the way it does.
8) Adelaide, Australia
This is the capital of South Australia. It is known as being one of the best places to live in the world. The fact that it is so clean is one of the reasons why.
9) Calgary, Canada
The Canadian city of Calgary has recently been recognized as being the cleanest city in the world. There are no words to describe it – just go there and see for yourself.