It is a drab autumn day in the 1980s: the skies are grey, the streets glisten with rain, the trees are bare.

BBC: Bringing the Berlin Wall back to life

Whitebeam trees marked the path to right and left, with their grey-green upper leaves and their sharp silver unders.

BBC: England��s ghostly South Downs Way

In the midst of a cacophony of cars and cabs on the historic cobblestones at Gansevoort Street is a grey metal staircase leading up to a zone of relative quiet amid a grove of birch trees.

BBC: Walking New York City��s High Line