We visited in mid October. To get to the entrance you have to walk through the botanical garden. When we were there all the paths trough the garden were roped off which was too bad as it would have been nice to walk through. Entrance fee is 6 euros each and you could spend about an hour to an hour and a half inside. For a small town mining museum they really did a good job with the displays. However, it would have been way more interesting if some of the displays could have had English translations. We were given a small pamphlet which we tried to read while walking through but it doesn't give information on specific exhibits but was helpful. If you are into rocks it is pretty interesting.