Formidable terrain made road building on the West Side particularly difficult. By the 1860s, a horsecar could travel up Eighth Avenue only as far as 84th Street before the way became impassable, and most of northern Manhattan remained a rural expanse. Steep hills with formations of Manhattan schist—a notoriously hard rock to cut—presented topographical obstacles that the 1811 grid ignored. In this view from 106th Street from about 1869, a team of laborers excavates through a hillside to extend Eighth Avenue north, using a crane to hoist large loose or loosened rock out of the path. The section of the hill visible on the right is today part of Central Park, where stone steps lead pedestrians up and over the ridge. Nothing remains of the hill on the left, which, like most of the natural topography of the West Side, was demolished to clear the land for development. CY