Number 3 in the Kennet Island mini-loop. Inspired by the now archived cache by the Edward Simeon monument in Market Place in Reading town centre, I'm sure those you found that one will have no problem with this, but if not, then like me you may struggle for some time...it took me a few visits to find the original and have my 'AHA' moment.
Use your stealth as GZ is quite overlooked.
Nearby visitor parking is available at the Piazza but there are regular patrols, so please obey the parking rules.