Elevated commuter trains (the "L") circle downtown Chicago, which is often referred to as the "Loop." Sections of the "L" were started in 1892, and most of the structure has a rather dated look. Being above ground, it is noisy if one is right next to it. On the other hand, while staying in a hotel two blocks away, the sound of the "L" was reminiscent of the surf when staying near the ocean.
One of the lasting impressions of downtown Chicago in Spring are the multitude of tulips -- a most pleasant surprise.