Complex sentence: Such cairns are often placed at junctions or in places where the trail direction is not obvious, and may also be used to indicate an obscured danger, such as a sudden drop, or a noteworthy point such as the summit of a mountain.
Split into simpler sentences: Such cairns are often placed at junctions or in places where the trail direction is not obvious. They may also be used to indicate an obscured danger such as a sudden drop, or a noteworthy point such as the summit of a mountain.