I went to the Britannia mining museum this summer and it was definitely worth the visit. The entry price for adults ($21.50) was a bit on the steep side, but I didn't feel it was a waste. The train ride and machinery demonstrations underground were the highlight. It's also rather mind blowing to walk into the old mill - a huge building that left us all looking up and gaping as soon as we walked in the door. Our tour guide was exceptionally good. He was obviously not a former miner at the site (too young), but he was very knowledgeable and spoke as if he had a great affinity to the place, the miners, and the mine's history. I'm usually not big on "welcome to our museum" films, but the one they show in the interpretation centre was very useful, to see old footage and picture what the mining towns were like when the mine was working. There was a senior with us (80ish) and there is a climb of several stories of wooden steps (no elevator) to get to the mine ride entrance, so we had to allow for plenty of time to get to the train ride on time.