We saw the sign

Hartle Lane - GC1NQCB

This too turned into a cache 'n' dash, more by luck than judgement.

We could see on the map roughly where the cache was going to be, and the clue was "sign". The point in question is where a B-road meets the A491, so there were plenty of signs around. I turned into the B-road and parked on the left.

As soon as we got out of the car, our GPSr indicated that we were right on top of ground zero - and indeed we were. I'd parked next to the direction sign for traffic exiting Hartle Lane onto the A491, and spotted the cache straight away - just next to one of the support posts on the rear of the sign, in a 35mm film cannister that was attached to the sign by a magnetic strip.

Just prior to finding this cache, it started to rain. We decided to leave the next cache in the series because it clearly involved a decent walk from the car. The cache after that is currently listed as "unavailable", so we moved on to the final two.