Follow the Rhyd-Ddu-Path. On Bwich Main, about 400m before you arrive at the summit you are close.
The cache is a tuperware box full of priceless treasures such as medals and coins.
Finding this cache will require a good walk and some scrambling.
The Cache has been placed with the kind permission of the National Trust
A grand and charming way up the mountain, the Rhyd-ddu Path is one of the least popular routes and also one of the most scenic too. Striking in from just south-west of the summit it offers tremendous views over to the quiet but spectacular hills of Moel Hebog and the Nantlle Ridge as well as onto the craggy cliffs of Llechog and the broad majesty of Cwm Clogwyn. While the bulk of the route is on wide, gradually rising paths, the final third is narrow and rocky. It doesn't compare to Grib Goch, but it's a far cry from the stately expanses of the Llanberis and Ranger Paths.