This site is best approached off the A496 at Llanfair, 1 mile south of Harlech at GR SH573295. In Llanfair turn inland, in 100 meters turn left them in 75 meters turn right. Follow this road for about three miles, straight over a crossroads and past a junction. Merthyr Farm (the campsite) is on the left. The trial site is a quarter of a mile further on the right. The site is at GR SH611321.