Here are a couple of pictures of the Super Kamiokande neutrino detector. My favorite one is the one on the side which shows the guys in the rowboat out in the middle of what looks like a lake. That huge chamber is filled with heavy water and then lined on all sides with Cherenkov detectors. This particular detector is located something like a mile under a mountain in Japan. Muons created by the interaction of cosmic rays with atoms in the upper atmosphere, probably atomic nitrogen or oxygen, have enough energy to reach the Earth’s surface and that would skew the experiment, so neutrino detectors were first constructed in abandoned salt mines.
The pictures are super high-resolution, so here’s a link;