One of the original squares from William Penn's town plan, this public space (named in honor of James Logan an 18th-century major) is centered on the Alexander Stirling Calder–designed Swann Memorial Fountain, with its large frogs and turtles eternally spouting water.

On the square's west side is Aviator Park, marked by the Aero Memorial and the All Wars Memorial, while on the east side is Sister Cities Park with a kids' play area, cafe and visitor center.