King Otto I, also known as Otto von Saxony I and Otto Der Grosse Duke of Saxony, was founder of the Holy Roman Empire.
Born son of Henry I of Germany, Otto became the first Holy Roman Emperor and earned the appellation Otto the Great.
Otto is also the name of our Rottweiler who's mission in life is to flatten the nettles and sniff out the caches.
NB: The cache location is close to a turning point on a cross-country Steeplechase course - so keep an eye out for horses.
No need to leave the comfort of your home to get the co-ords:
The cache co-ord are N52.35.ABC / W001.18.DEF
A = Otto reigned for how many more years (not his age) than 30?
B = Otto became king in how many years beyond age 15?
C = Otto wed Adelaide how many years after 950?
D = Otto was born how many years before 915?
E = Otto was crowned Roman Emperor on what date in February?
F = Otto and his united armies of Germany defeated the Magyars on the valley of the Lech how many years before he became Roman Emperor?
The sum of A+B+C minus the sum of D+E+F should = the square root of Roman Numeral XXV
Please make sure that the cache is well hidden