Of all meteorological phenomena - from puffy white clouds to dramatic lighting strikes - the rainbow is surely the most universally loved. Coming, as it does, on rainy days, the rainbow can be seen to represent a promise of better times after adversity or hardship. The many beautiful shades of a rainbow have also come to stand for the wonders of human diversity.
The rainbows in these pictures are certainly diverse in terms of setting, standing as they do over some of the greatest cities in the world - from Sydney (pictured above) to Istanbul. So let's take a look at some more metropolises framed by one of nature's most beautiful creations.