Blue doors

There's nothing special about these double doors. I've never seen them open. But they always attract my eyes, and my curiosity.
Why?

The light blue colour of a winter sky; 
the  multiplicity of hinges, suggesting they open in a complex pattern; 
the wisteria that has arched itself across the top; 
the stone gate post which indicates there was a wide entrance here once; 
the silver birch beside it with witches broom tangles;
the cucumber-green corrugated tin (a common building material in these parts) of the structure itself.
and the neatly placed downspouts to carry away rainwater.

Whatever could be revealed inside is unlikely to be so satisfying.