The road for Lyme (marked on maps as the A 3052) peels off at such a narrow angle that for a while it hugs the side of the larger highway. (Really we should say that the highway hugs the side of the smaller road, which is older.) Then it rises among trees up a steep bluff, called Fern Hill. The road emerges in a more open piece of upland. A small lane meets it on the right.
The lane looks interesting (it seems to continue the line of the road you were
on) so you let yourself get diverted
Or stay on the larger road as it swings around
to the left.