Beneath a rusted bridge

Here opens a small crag just outside an steep earth embankment, and just
beneath what appears to be a large and somewhat decrepit bridge. The
stench of sewage wafts from the gaping hole in the embankment, and the
nearby rush of what sounds like a large river can be heard, though you
can't seem to see it from here. You can climb up to the bridge from
this spot, though from the looks of it the narrow passage upward would
be too precarious to enable you to make it back down.

Obvious exits:
North - A darker junction
Up - On a Long, Rusted Bridge