Concrete Megalith at Penn's Landing

There is a four-story Welcome to Penn's Landing sign here that was supposed to have been a base for a tram that crossed the river into Camden, NJ, a part of a big entertainment complex that never was built. See Inga Saffron's column in the Philadelphia Inquirer, 6/28/15, at p. H 19, where she calls it the Waterfront's Stonehenge. This Web page calls it the Penn's Landing Pi, as it resembles the mathematical symbol, and has a nice photo of it: http://phillyskyline.com/summerofthedelaware/05.htm.