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SideTracked - Marston Vale Line - Ad Lab Bonus Mystery Cache

Hidden : 07/25/2021
3 out of 5
1.5 out of 5

Size: Size:   micro (micro)

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Geocache Description:

SideTracked - Marston Vale Line - Adventure Lab Bonus

(Another option for SideTracked Day 2021)

The Marston Vale line (Network Rail route MD 140) is a rural line between Bletchley and Bedford, a surviving remnant of the former Varsity line between Oxford and Cambridge, most of which was closed in the late 1960s. The line is sponsored by the Marston Vale community rail partnership. The line is to be adopted and upgraded as part of East West Rail, a project underway to re-establish the Oxford–Cambridge route.

The line was opened in 1846 by the London and Birmingham Railway, though the L&B merged with the Grand Junction Railway to become the London and North Western Railway whilst construction was ongoing. The line later became part of the cross-country Varsity line from Oxford Rewley Road to Cambridge. Much of the line was built on land owned by the 7th Duke of Bedford, who supported the line but insisted that any station on his estate (Fenny Stratford, Woburn Sands, Ridgmont and Millbrook) be constructed in half-timbered style.

The line was threatened in the late 1950s and again in 1964 – though the Bletchley to Oxford and Bedford to Cambridge sections succumbed in December 1967, the Bletchley to Bedford section survived.

Silverlink operated the line from privatisation in 1996 until 2007. London Midland took over in 2007 until 9/12/2017. On 10 December 2017, West Midlands Trains took over the franchise, staff and rolling stock, operating as London Northwestern Railway. An hourly service operates in each diirection Monday–Saturday.

It is one of a number of British Railways that is covered by a Community Rail Partnership, in this case known as the Marston Vale Community Rail Partnership. Like other Community Rail Partnerships around the country, the Partnership aims to increase use of the line by getting local people involved with their local line. They do this by various means, such as holding community events, running special train services, and publicising the line locally.


These adventure labs will take you to visit stations along the railway. They can be done in any order, by train, road or bike.  The bonus has been designed so that it can be found once you have visited at least 4 or the 5 locations on the Adventure Lab.

This cache is NOT at the posted coordinates.

To find this mystery cache you will need to complete the SideTracked - Marston Vale Line Adventure Lab. 

Each time you complete one of the five stages of the adventure labs you will be given a bonus code for this cache. 

Once you've got 4 of the 5 bonus codes, you can use the checksum A+B+C+D+E = 21 to work out  the fifth (or you can visit the fifth location). This is because the cache is part way along the route and is nearer Stewartby station than any of the others.

The cache is at:

N 52° 4.ABC' W 0° 30.DEC'


Additional Hints (Decrypt)

Ovfba - Jbbqra Cbfg

Decryption Key


(letter above equals below, and vice versa)