In the Finger Lakes Region of New York State, the retreat of the glaciers during the last ice age left numerous small, rounded cobblestones available for building. Pre-Civil War architecture in the region made heavy use of cobblestones for walls. Today, the fewer than 600 remaining cobblestone buildings are prized as historic locations, most of them private homes. They are clustered south of Lake Ontario, between Buffalo and Syracuse. There is also a cluster of cobblestone buildings in the Town of Paris, Ontario. In addition to homes, cobblestones were used to build barns, stagecoach taverns, smokehouses, stores, churches, schools, factories, and cemetery markers. The history of building with cobblestones and 17 driving tours to see the remaining structures are found in "Cobblestone Quest - Road Tours of New York's Historic Buildings". (per wikipedia)

What's a cobblestone? Cobblestones are small rocks that can fit in the palm of your hand. Pioneers to western New York State found the cobblestones, which had been brought by glaciers, along the shores of Lake Ontario or in the fields they tried to plow. They used them to build their homes, schools, churches, smokehouses, etc. 90% of all cobblestone buildings in the United State are found within a 65-mile radius of Rochester, New York. (from "Cobblestone Quest")