My muse is inspired a bit from my roots back on the West Coast in Portland, OR. We're literally the city of bridges, with 12 total. I've always thought they looked cool, whether as the focal point of a photograph or something in the background.
My particular muse is the Williamsburg bridge which leads from Williamsburg Brooklyn into the Lower East Side of Manhattan.
Outside of the Brooklyn Bridge, I think it's the most interesting in New York. The architectural structure is really cool and makes for really interesting lines while the colors are also a bit unique and play off of eachother in a cool way. Your angle, location, time of day, and weather can all make for really unique shots that can feel majestic, industrial and gritty, all at the same time.