This image is similar to one I just rated by psychodudu. I posed the question, "if you weren't posting this shot for the curves theme would you still find it interesting?" For his image, I thought the answer was no since it was solely about the walls and arches of an otherwise anonymous building.

However, the arches in this shot are part of a larger scene which even includes their reflection on the river. I don't find the skyline particularly interesting, but overall I think the image is much more appealing.

As King would say, IMHO of course.

I like the curves and lines, though to my eye there's no particular subject that really pops out.

I love arches and other such curves, and here we have graceful reflections as well. The graceful swans necks of the street lamps contribute their share and lead the eye into a muted but beautiful sky, with its wispy curves of cloud.

I probably would have cloned the billboard out of the photo, but you may not have Photoshop available.

A lovely photo, all in all.