City scaping during the blue hour

Peter and I went to Groningen for some blue hour photography.
I was busy and crowded in the city, but the colours were spectacular during a short period of time. The Vismarkt changed into purple tones during the blue hour.
We had a lot of fun during the few hours we were there. It amazed me how many people stopped and asked what we were doing. Somehow, a camera on a tripod attracts attention.
It was also funny to see how many people took out their phones to capture the sunset as soon as they saw us with our cameras pointed at the sky.

This photo was made using the LEE big stopper, and had and exposure time of over 9 minutes.