Limestone is very common in architecture, especially in Europe and North America. Many landmarks across the world, including the Great Pyramid and its associated complex in Giza, Egypt, are made of limestone. SOn the island of Malta, a variety of limestone called Globigerina limestone was, for a long time, the only building material available, and is still very frequently used on all types of buildings and sculptures.
Limestone is readily available and relatively easy to cut into blocks or more elaborate carvings, which now hold the key writings from this time. As we can see it is also long-lasting and stands up well to exposure.
So limestone is great for sharing, which is in part what a letterbox cache is good for. Please remember to leave the stamp in the cache container.
