Until recently, street art was a very under-appreciated art form.

A lot of times, street art unambiguous, although the artists themselves are often unknown. Perhaps the reason is that street art is treated like graffiti, seen as defacing structures and could be illegal in many places.

ALSO READ: Sculpture erected in honour of cat

Many times, these paintings bring out, or complement the beauty of the urban landscape, transforming it into something amazingly beautiful.

Street art seems to appear spontaneously, instantly drawing attention of passersby and the local populace while passing it's message across.

Here are 10 of such amazing pieces from around the world:

1. In New York, America:

2. In Stavanger, Norway:

3. In Oz, France:

4. In Berlin, Germany:

5. In Milan, Italy:

6. In Hong Kong, China:

7. In Weston-super-Mare, Britain:

8. In Karlsruhe, Germany:

9. In Croatia:

10. In Kalamata, Greece: