From 1861 until 1965, the Portpatrick and Wigtownshire railway -
the Port Road, as it was familiarly known - meandered across south
western Scotland, from Dumfries to the ports of Stranraer and
Portpatrick. Despite its usual name, it wasn't built as a single
through route; though later part of the Glasgow and South Western
Railway, it had a history as picturesque as its line. The most
spectacular part was built by an independent company known as the
Portpatrick Railway, which ran from Castle Douglas to the harbour
for the Irish Mail packet steamers at Portpatrick - this was the
shortest sea crossing to Ireland, and was before the superior
harbour at Stranraer was developed as the speed of steamships
improved.

New Galloway Station in the 1950's
Although the route closed in 1965, many of its
substantially-built structures survive today. New Galloway station
(actually in Mossdale Village), is now a private dwelling
house.
For more information about the Portpatrick and Wigtownshire Line
click here
The cache is located in an area formerly used as the station
yard, if you take the short walk towards the station you will note
the rail bed still exists and is very popular with off road
cyclists. Note also that there are a number of very pleasant walk
routes which start from here - there is a small plaque depicting
the routes near the entrance to the parking area.
You are looking for a 35mm film canister
FTF - Headie D