Switzerland is a small country draped over some tall mountains, yet it has developed ways to pack all kinds of modern infrastructure in with Swiss engineering and multiple uses of the land.
Now, airports and military air bases need quite a bit of room and flat ground for runways, which is at a premium in Switzerland. So they built Meiringen Air Base in 1941 in an Alpine valley that had civilian roads running through it. The highways run right across the runways! Yeah, there's a system in place to keep everyone safe. The planes have the right of way on takeoff, because they can close the highway crossing, but automobile traffic has the right of way for landings, since a plane can circle until they can close and clear the highway crossings.
Most air bases are closed to the general public, but it can't be done here, so people come from all over the world to watch the military aircraft take off and land at Meiringen. Tom Scott added some more information at the YouTube page, explaining that the planes aren't stored in hangars here. They are parked in caverns in the hillsides! The Swiss know a thing or two about saving space.