The difficulty in North Wales is in the pockety nature of the gold deposits - it is far easier to plan out and execute a mining operation if you have e.g. a lode with a strike length of a kilometre, with drill-confirmed continuity down to say 500 metres and a consistent gold grade of say 10 grams per ton of ore. By contrast, a lode that carries irregular pockets of much higher-grade ore, separated by low-grade or barren ground, requires a lot more technical work if a profitable mine is to be established, even at Welsh gold premium values.