What is cairn definition?

A cairn is a man-made pile of stones, often used as a trail marker in areas with little or no vegetation. Cairns can range in size from small piles to large structures and can be found throughout the world in various forms, including circular, rectangular, and pyramid shapes. They are often used by hikers and other outdoor enthusiasts to mark a trail or indicate a safe route through difficult terrain. Cairns have been built for thousands of years and have been used for a variety of purposes, including religious, ceremonial, and practical reasons. In many cultures, cairns are considered sacred and are seen as a connection to the spiritual world.