One of the earliest maps of New York City, the Castello plan shows Dutch New Amsterdam in 1660. This original street grid still exists today but has been enlarged with landfill since the city was founded. As illustrated on the map, Pearl Street was the original East River water line, named for the pearly oyster shells along the shore. New landfill in the East River pushed the shoreline to 'Water' Street, then 'Front' Street, both named for their frontage along the water. South Street was the last street along the East River created from landfill. The historic Castello Plan street grid is now landmarked.