Philadelphia World Park Solar System Walk
☉ World Park: Orders and Perspectives
Starts at ☉ World Park: Orders and Perspectives. You'll get directions there, then scan the GO code on your card when you arrive.
A true-scale walk west across Philadelphia, from a mosaic globe at 12th and Filbert out to the far edge of West Fairmount Park. The whole inner solar system fits in the four blocks around City Hall — Mercury to Mars is a five-minute stroll — and then it opens up: Jupiter on the Parkway, Saturn at the top of the Rocky Steps, and Neptune four miles out behind the Mann Center. About 4.2 miles end to end, almost all of it downhill-flat and walkable in an afternoon.
The Sun
☉ World Park: Orders and Perspectives
Ned Smyth's 1995 mosaic environment on the Marriott plaza at 12th and Filbert — an arcade of columns ringed by trees, with an abstracted globe of the world at its centre. That globe is the Sun for this walk, measured on site at 7 feet across, which sets the scale of everything that follows at roughly 1 : 652,000,000. Marriott fenced the plaza in 2025, so the globe is something you look at from the 12th Street sidewalk rather than walk up to — which changes nothing about the walk. It's there, you can see it, and your card is what the AR measures against.
See this stop →Getting there
The route
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Want to do this in your city?
The mission builder lets you place any real-world landmark as the Sun and generates a true-scale walk from there. Walks you create can be submitted to appear here for everyone.