The Elfreth's Alley Museum sits on a 15-foot-wide cobbled lane that started life in 1702 as a shortcut to the Delaware River. Somehow, through yellow fever, demolition plans and the construction of Interstate 95, it has managed to remain the oldest continuously inhabited residential street in the United States.

The street takes its name from Jeremiah Elfreth, a blacksmith who rented houses here to sea captains, stevedores and shipwrights. Today, two of the smallest dwellings function as the museum, preserving the cramped reality of life on the alley when a single doorway served as both family home and shop front for shoemakers, seamstresses and grocers.

VoiceMap's self-guided audio tours use the alley to decode Flemish bond brickwork, trace Philadelphia's brick-built defiance of fire, and follow the immigrants, soldiers and Quaker neighbours of Benjamin Franklin who walked these stones.