Circumzenithal arc over St James's Park

A circumzenithal arc spotted over St. James's Park, London, at about tea-time - we were drinking tea when we spotted it.

If you look closely, you can see a second arc lower down. They're formed by light reflected from ice crystals in a cirrus cloud between 8 and 10 miles high.

For more on circumzenithal arcs, click here.

Here's one I saw over Suffolk four years ago.