A guard stone is a sturdy building adornment positioned where cars or other traffic vehicles have a high probability of making contact with the building and damaging it over time. These stones were first put into use by property owners who observed that people who drive horse-drawn vehicles are often not aware of the necessary turning radius needed to avoid bumping into buildings. As the metal axle protuberance through the wheels of wagons would chip away at corners of buildings over time, guard stones were put in place to provide a substantial object to protect the building from damage.
Some guard stones are attached to a building, while others are placed some distance away. Often, a guard stone is placed at the corner of a building that lies at a crossroads where vehicles are more likely to come into close contact with the building due to turning. In Europe, guard stones are often attached directly to a building, while in the United States guard stones are more often placed some small distance away from the building, like a curb line in a parking lot.
Curbs serve the same purpose for the modern era as a guard stone served before 1900. The change in the form of the guard stone mirrors the change in function. Guard stones were once taller, larger and would be very close to buildings. After the 1900s, tall guard stones adjoined to building corners were less necessary to prevent damage to buildings because people would be more careful about refraining from causing damage to their own cars.
Due, however, to the lack of available visibility from within an automobile, car drivers would sometimes have trouble gauging the distance between their car and a building they meant to park near. Curbs were soon implemented to prevent cars from hitting the building, but they were built low to the ground and farther from the building than traditional guard stones to address the change in solution necessity due to technological advancements. On roads, guard stones are often made of concrete or steel and they're rarely decorated.
Against a building, however, a guard stone is more likely to be decorative, functioning as a building adornment, as well as a practical damage prevention measure. Guard stones are often made of rock or metal and can be sculpted, molded, bent, or otherwise crafted into a work of art. In many Eastern countries, it is common to find the main purpose of a guard stone is now to serve as decoration since, in some cases, guard stones are no longer necessary where they once were.