A Once and Future Shoreline is a permanent public artwork that graphically marks the edge of Boston Harbor, circa 1630, into the granite paving blocks of the plaza on the West side of the historic Faneuil Hall building. The 850-foot-long artwork depicts the location of a pre-colonial shoreline by graphically etching silhouettes of materials that are found typically along the high tide line. The artwork offers a way to engage the imagination in an exploration of the changes to this now urban site from a salty tidal marsh, to an active pedestrian plaza.