Seeing a rainbow at the Golden Gate Bridge was a unicorn moment for me! I have taken numerous photos of this bridge, but this moment will always be special. I was showing popular photo spots at the bridge to a friend who was doing a road trip across the western US. We were at the spot where the Transamerica Pyramid aligns with the top window of the north tower of the bridge (this is often referred to as "thread the needle" shot), and a rainbow suddenly appeared. Intensity of the rainbow grew for a few a moment's before it disappeared and grey skies loomed over.