CMS Compact Mudon Selenoid experiment in CERN Centre Européen de recherche Nucléaire, Geneva Switzerland. Part for the LHC Large hadron collider. These incredible pictures of the inside of one of the experiment of CERN have been made possible through meeting Maximillien Brice. Max is the head photographer for CERN and has become a personal friend of mine. So when he called me to tell me that the LHC was being stopped for some maintenance and that we had a small window of opportunity to go down on monday the 7 th of ferbruary I couldn't not jump on the occasion. 18:30 we meet in front of the information center of CERN which is on the Swiss side near the village of Meyrin. You have to know that the LHC is a huge circle tunnel that covers tens of kilometers at an average of 100 m under the surface of the canton of Geneva in Switzerland and the department of Ain in France. Along this very long tunnel filled with high end technology and supra conductor magnets there are various caverns hosting experiments related to finding the boson of Higgs. One of the is the CMS or compact mudon solenoid. After driving for 15 minutes on the French side we reach the small village of Cessy near Gex. It's there that lays one of the shafts that is going to take us down to the CMS. Before going down we have to wait a couple of minutes for the supervisor who will be accompanying us down. This facility is under very high security. Each staff member caries a huge pass around his neck the size of a cell phone. This device is also a densitometer that records the level of radiation that the personel is submited to. Iris recognition doors complete the security system to make sure absolutely no one enters without proper surveillance. As we are allowed access to the CMS cavern we will be very close by some other parts of the experiment of which some soldering will be Xrayed to check for defects. So they don't want me wandering around. This little wait gave me some time to take two panoramas of the control rooms. These control rooms are not as impressive as the ones in ATLAS but I'm always amazed by the quantity of monitors staked on top of each other and basically covering the entire field of view. It's now time to go down. Our guide takes us through the various security devices and into a large elevator down some 100 m, it take a bit of time. At the bottom we had to walk through maze like tunnels to reach the cavern. And there it is. 6 stories high xxx meters long. The detector is a stack of gigantic donuts of technology that have been lowered down layer by layer into the cavern and stacked horizontally. At both ends there is about 10 m of free space in front of the detector to take pictures. I was even able to use one of the elevator chariots to position my camera in mid air right next to the detector. The guide and myself had to cuddle up underneath the camera as there was no space to rotate around it. I used a Roundshot D3 camera fitted with a 24mm calibrated mamyiia fisheye lens to take these one time shots. Each picture took about 8 minutes to capture in a very slow scan. The resulting picture was a 180 million pixel 19'000x9'500 16 bit tiff file. In about two hours I was able to catch 6 incredible panoramas from above, under and on the catwalks around the CMS. And now thanks to Max Brice and the staff of CERN I'm able to share them with you. Enjoy the visit and make sure you leave some comments or questions.