This cache is the bonus for the 'Treasure at Clare Station' Adventure Lab cache series. It is NOT at the given coordinates (see below).
There is also a nearby mystery/puzzle cache GC93CKX (The Railway Cats of Clare Station).
The Treasure
Clare station stands amid the ruins of a medieval castle. The construction of the station in 1865 included digging through part of the castle earthworks to make an access road.
During the construction, workmen discovered a beautiful engraved pectoral cross and chain made of gold and pearls, and dating from the 1400s. It had originally been enamelled and would have been worn on the chest.
The cross was a reliquary as there is a cavity inside where minute fragments of wood were found. Many people would have believed these to be fragments of the 'True Cross' on which Christ was crucified. These relics, the craftsmanship and the precious materials used to make it would have made the cross incredibly valuable. The cross probably belonged to Cecily, Duchess of York, mother of both King Edward IV and Richard III, and it may originally have been made for Edward III.
The workmen who handed over the cross probably got little more than a 'thankyou' in return for their honesty. Even the landowner missed out as the treasure was declared Treasure Trove and is now safe in the Royal Collection.
So that's the history. But there is also a legend (amongst Geocachers at least) that there is a second cross (a bit less valuable) to be found somewhere in Clare, a cross which contains not a holy relic but a humble log to be signed by those whose quest leads them to it. If you do find it be aware that the legend also speaks of a curse that will befall anyone who dares take it away from its hiding place!
The actual coordinates can be found in the JOURNAL for the final stage (Treasure on Station Road) of the Adventure Lab. Open the journal page after you get the final ‘Completed’ message.