Ringed by busy roads, this square – one of the originals from William Penn's masterplan for his new city – feels somewhat cut off from the other sights of the Old City. Nonetheless, you will find a pretty fountain, a carousel ($3) and a mini-golf course (adult/child $9/7), as well as a seasonal burger shack.
The square has suffered mixed fortunes over the centuries, at one point partially containing a burial ground and at another labelled a Skid Row for drunks. Since its maintenance was contracted out to the non-profit History Philadelphia, and the family-friendly features were added, the square's fortunes have been on the up. A great time to visit is in May and June when the Chinese Lantern Festival brightens up the space with 1500 silk lanterns and performances by acrobats and folk dancers.