Wealthy Weather

As I was walking across London Bridge yesterday I noticed that on the north side the weather was clear, yet just across the bridge towards the south it was totally overcast and grey.

Anyway, these confused weather conditions spawned a rainbow, which viewed from London Bridge seemed to end in one of the towers of Tower Bridge. I recalled the old myth that at the end of each rainbow lies a pot of gold and thought to myself at least I know where to go if I need some spare cash...