Special tool required.
Warning - very steep slope and close to the river at stage two.
You need to measure five dimensions of the gate, rounding your measurement to the nearest whole number.
Height of gate = AB inches
Width of gate = CDE centimetres
Depth (thickness) of gate = F inches
Height and width of grid squares = G centimetres
Vertical gap between bottom two bars of gate = HJ centimetres
Checksum (AB + CDE + F + G + HJ) = 167
The cache is at N 54 12.J(B-C)(F+G) W 1 19.JBH
Part of a mini-series of caches; all of which require a (different) special tool.
You must sign the paper log in the cache to be able to log online as "Found". I reserve the right to delete your online log if you haven't signed the paper log in the cache.