Over the past few years, the once drab plaza around Philadelphia’s magnificent Second Empire-style 19th century City Hall has been transformed into a welcoming gathering place. Last month, the newest component of the Dilworth Park project was launched with the initial phase of the beautiful “Pulse” fountain installation. Created by artist Janet Echelman, “Pulse” traces the surface path of the SEPTA subway Green Line which runs beneath the plaza. As trains travel below the square, vibrantly colored mist erupts from a walkway in the fountain. Utilizing a high pressure misting system and LED illumination, a fog-like curtain rises from the fountain.

The installation, which is meant to evoke the steam that rose from the old Pennsylvania Railroad Station that stood across the street from City Hall during the 19th century, will eventually include a Blue Line and an Orange Line section as well. But for now, the “Pulse” at the northern end of Dilworth Park is drawing crowds nightly.