In general, I prefer taking landscape photos. However, I also don't mind experimenting with city photography.
Last year I was visiting Luxembourg city with some friends. One of the landmark buildings in Luxembourg is the Philharmonie, the opera and classical concert hall located on the Kirchberg Plateau. One of the key features of (the outside of) this building are its columns. It features 823 round facade columns made of white steel, which are arranged in three or four rows.
I took this photo at night, and decided to turn it into black and white, to stress the lines and the gradients of shadow on the round columns. Selecting a square format results, in my view, in a nice balance of lines.