This cache is placed where the Heart of England Way crosses the remains of a bridge which used to be part of the railway line between Great Alne and Alcester. The railway was finally decommissioned in 1951, but the route of the track can be clearly seen from maps and aerial photographs. This area around the bridge was known by locals as "Sandy Banks". An internet search will reveal a fascinating then and now video of the area.
You are looking for a tiny magnetic nano with only a logbook. Please be careful to replace it exactly where you find it.