Cairn (noun)

1. A pile of stones or rocks used as a landmark or memorial, especially in the form of a monument or tower.
2. A pile of stones or rocks used to mark a trail or a boundary.

Origin:

Mid 17th century from scottish gaelic 'càrn' meaning 'a heap of stones'.

Examples:

1. The hikers left a cairn at the top of the mountain as a marker.
2. The cairn was a symbol of the couple's love, as they placed a stone on it every year on their anniversary.
3. The cairn was so tall that it could be seen from miles away.
4. The cairn served as a trail marker for those who wanted to reach the summit of the mountain.
5. The cairn was a popular spot for tourists who came to take pictures of the surrounding landscape.