What it is: The Blue Rigi, Sunrise (c. 1842), a watercolor by J.M.W. Turner showing Mount Rigi in Switzerland seen across Lake Lucerne at dawn.
Where it is: Tate Britain, Millbank, London SW1P 4RG. Open daily 10 a.m.–6 p.m., free entry for the permanent collection.
Why it matters: Turner made three Rigi watercolors — blue, dark, and red — and this is the one in which the mountain almost dissolves into weather. It was sold at auction in 2006 for a then-record price for a British watercolor and acquired by Tate with Art Fund support. The blue is not a single pigment but layers of cobalt, ultramarine, and washed-out graphite that shift as you move.
