Geomorphologically, a Volcanic Neck is a “residual” landform of volcanic origin. Shiprock in New Mexico and Devil’s Tower in Wyoming are classic examples. These features provide geologists with a rare look at the internal “plumbing” of ancient volcanoes. Because the basalt or granite that solidifies in the vent is much harder than the ash and cinder forming the surrounding cone, it survives long after the rest of the mountain has vanished. This process demonstrates the power of differential erosion—where different rock types wear away at different rates, creating striking, isolated landmarks.