First of all it is hard to find this place as there is really nothing announcing it. Then you go in the courtyard and try to find the place to buy tickets (all the signs pointed the wrong way when we visited! The ticket counter is directly across the courtyard). But the real trick is to know to show up as close to 10 am when they open and buy tickets for the 1 pm tour. This tour is twice as long as the normal tour and takes you through the scientific halls of the museum. Only 15 tickets are sold for this tour as opposed to the 45 or so crammed into the short tour. Seeing all of the fascinating relicts so up close and personal is a rare treat and you really feel privileged to participate in the experience. Truly a hidden gem for the patient and determined traveler.