London not only has a world-class reputation for art in its many galleries, but also a remarkable range of art outside in the streets.

We tour around the capital discovering some of the most interesting works from across the centuries.

They range from huge and expensive commissions to unofficial graffiti, which is sometimes audacious and often playful, but they all have a place in our society.

We look at why art is there, how it has developed over the years and discover many hidden gems.