I know its tacky, but how about the Blaenau FFestiniog game? You obviously need to be careful at Minffordd to avoid a Portmeirion plasma flux, but is anyone brave enough? And don't be fooled by the apparently simplistic linear nature of the line. ahem Porthmadog!

Well, Tan-Y-Bwlch seems to be a safe move at this point.

Penrhyn then.

Tanygrisiau, predictably enough.

Trawsfynydd nuclear power station - I know it rather detracts from the landscape, but I can't help that. There were so few options.