In major museums around the world, some truly great works of art are hidden away from public view. What are they - and why can't we see them? BBC's Kimberly Bradley finds out.
BBC: Why museums hide masterpieces away
An Iranian woman admires a painting by US artist Jackson Pollock, titled as \"Mural on Indian Red Ground\" (1950), after the inauguration of the \"Modern Art Movement\" exhibition at Tehran's Museum of Contemporary Art, 29 August 2005.
