Halton is a relatively small borough, mostly centred on the towns of Widnes and Runcorn, but also including the parishes of Hale, Halebank, Moore, Daresbury, Preston Brook and Sandymoor.
In this series, we visit Halton's extreme points! It will take you as far north, south, east and west as it's possible to get in the borough. In each cache you'll find part of the coordinates for the bonus cache.
This cache takes you to the far west of Halton, out beyond the village of Hale where the borough juts out to the south of Speke, on the eastern edge of Liverpool John Lennon Airport. The actual westernmost point is just further down the road by the airport's perimeter fence, on the opposite side from GZ, but this wasn't an appropriate place to hide a cache.
Don't forget to note down the partial coordinates for the bonus!