Nantucket is known for it’s cobblestone streets. The cobblestones in the streets of Nantucket’s historic district were actually ballast stones used to keep ships coming to Nantucket for whale oil stable and seaworthy when they were empty. When the ships would arrive at Nantucket to take on a load of whale oil they would empty their ship of ballast stones and these were used to make the cobblestone streets. Cobblestone streets are not friendly to riders of skateboards or rollerblades.