Co-ords are for The Rusty Laptop. No cache there.
The first performance was in August ABCD. (To clarify, this is the first performance on the new stage, well after the 70's)
Back in the ‘70s Crystal Palace was host to a few famous bands. The festival was known as Crystal Palace Garden Party and ran from 1970 to 1980.
Amongst the famous names were Beach Boys, Elton John, Eric Clapton, The Faces, Pink Floyd, Roxy Music, Bob Marley, Santana, Elvis Costello and Rick Wakeman
Pink Floyd appeared on the bill in 197E, Rick Wakeman appeared in 197F, The Beach Boys in 197G and Elvis Costello in 197H.
Cache can be located at N51 25.GB(C-B) W 000 03.C(H-G)F
(Checksum for all numbers – 45)