That Embarcadero Center and those back stairs get my juices flowing every time. This one is based on a single, handheld exposure using the Zeiss Milvius 25mm f/1.4, exposed at 125 of a second, f/1.4, and ISO 1250.

Some related images: Spirals, Endless Stair, and Calling Alice. By coincidence, in a life cycle spiral, I had my oldest son Julian with me yesterday when I made this photo, just as I did many years ago for the earlier versions.