We visited 4 churches this afternoon in order to discover Geocaches hidden in the churchyards. This is a series of linked caches and each one had a puzzle in it which we had to solve in order to get some digits. We would then need to put the digits together as a grid reference to lead us to the last (and hidden) cache in the series. We answered all the questions - which involved looking for certain individual's gravestones in order to find their age, or dates on the side of the church, or the number of villagers who had died in WWI, etc. It was so cold though that we decided to come home and figure out the coordinates of the hidden cache in the warm.
It took a while but, thanks to Joe's mathematical prowess, we now have it cracked! Our next adventure will be to go and find it - perhaps it contains gold coins!