The circle on top of the polygon ( I can't tell how many sides but clearly more than four) juxtaposed with the rectangular lines of the newer looking building and then the curves of the rail--all very nice elements. But I like the stunning blue sky best. I just love those deep blue skies.
I like how you have captured more than just architecture. Nice junxtaposition of ..old/new, curve/angle, convex/concave, and negative/positive space. You really captured so much that can be driven to metaphor in this image. Nice job.