Logan Circle began as the city's North-West Square but was renamed in honor of James Logan, William Penn's colonial secretary and administrator. By the middle of the nineteenth century, it was a fashionable residential square, bordered by three-story Greek Revival town houses. With the construction of the parkway, the square was reconfigured as a traffic circle to conceal the slight shift of axis between City Hall and the Fairmount Art Museum. Jacques Greber proposed to make the circle a significant feature of the parkway. With the impetus of a slowly maturing fund established in 1878 to celebrate the memory of Wilson Cary Swann, M.D., Wilson Eyre Jr. was commissioned to design a general scheme of a fountain surrounded by plantings in the midst of the parkway. The centerpiece is Alexander Stirling Calder's Fountain of the Rivers. Commonly known as the “Swann Fountain” for Calder's visual pun using giant swans to commemorate the donor, its spectacular water display celebrates the three great waterways of the region: the Delaware as god, the Schuylkill as goddess, and their little sister, the Wissahickon.
On the south side of Logan Circle at 1900 Benjamin Franklin Parkway is the Academy of Natural Sciences, which is a 1902 colonial-style refacing in red brick and terra-cotta by successors to Wilson Brothers of the deteriorated serpentinite facade of James H. Windrim's original Victorian Gothic building of 1868–1875.