On which meridian was this cache placed?
The answer : Greenwich meridian
The Mission 10b: Meridian Snake geocache (GC12AD) was hidden on 27 July 2001 in England. It was part of Project A.P.E., 20th Century Fox's promotional operation for Tim Burton's Planet of the Apes: fourteen caches scattered around the world that summer, each holding a genuine prop from the film (Markwell listed them). It was the only one of the programme in the United Kingdom, and it held 2 tickets to the premiere on 14 August. The tenth mission had been split in two: a cache in Georgia was released the same day.
The launch was botched. The published coordinates gave a west longitude instead of east, which sent searchers “into the middle of a sheep field”, as the first of them put it. The mistake was corrected the same day with apologies. The next day, with the coordinates put right, Richard & Beth took the FTF. As they were getting married abroad the week the film came out, they left the tickets for someone who could make use of them.
That someone was harold1066, out looking for his very first cache. Empty-handed on 28 July — his GPS was not set to the right format — he came back on 29 July, found the instructions for obtaining the premiere tickets, phoned the given number several times, left messages, and never got his seats. A shame!
After it was archived, British geocachers placed a replica in the same spot (GCTK7X), since archived as well.
The answer : Greenwich meridian