Cairns in the mist
A cairn is a pile of stones that says someone was here and found the way. On a clear day you barely notice them. In mist they are the whole route.
Last weekend the cloud sat on the ridge from first light. Between the third and fourth cairn there is a long flat stretch where the path fades into peat, and without those stones I would have drifted south into the bog. I rebuilt one that had toppled and added a stone to two others. It is the small tax you pay for using them.
Rule I keep: if you cannot see the next cairn, do not leave the last one until the cloud lifts. Ten minutes of patience beats an hour of relocating yourself.