O tour é fantástico e vale a pena fazer. Fiz a opção em inglês. Dizem que precisa agendar, mas cheguei lá (sem agendar nada) e entrei num grupo que estava iniciando naquela hora mesmo. De ônibus

We pretty much had our own private tour as it was so quiet. I thought this place was absolutely fascinating well worth a quick 30 minute visit

Actually it is the coldest! Boring scientific fact but it is colder than the average temperature of the universe. Even if just to see the free visitors centre, it is worth the trip. Take the number 18