This former railway line linked Selby to Market Weighton via Bubwith and Holme on Spalding Moor. The line was a single track opened in 1848. The line closed to all traffic in 1965. It hadn't been a very successful line. It's now known as the Howdenshire rail trail and you can walk from Holme on Spalding Moor to Bubwith.
This cache continues the series placed by others and when you get to GZ you'll understand the title. The cache is a nano.