The Vertical Bog is the section of the Naro Moru route between the Met Station and the alpine plain — a steep, saturated moorland of tussock grass and giant heather on the western flank of Mount Kenya. Its reputation among trekkers is legendary, and it has been the source of many wet socks and ruined boots.
There is no real bog in the technical sense, but the slope holds water like a sponge, and after rain the trail becomes a sequence of mud-filled hollows between clumps of grass. The way through is to step on the tussocks rather than between them. In dry weather the climb is manageable; in wet weather it is exhausting. Either way, the views back over the rift valley as you climb out are worth the trouble.