Cache Inspired by GC237NE by "MaMiFKA", with over 8000 attempts at a solution.
"Bang" is here
The Grid SW corner is N DD.680 E DD.630
The Grid NE corner is N DD.720 E DD.670
Identify a likely grid square, and test it's co-ords on the GeoChecker,"wrong" selections may give useful info, some Latitude (pun intended) is built in.
When You get The correct co-ords, Geocheck will give important information.
MYGEO1