The car coming down as we were going up on the Nerobergbahn.
The Nerobergbahn is a little two car train system that runs on water. They fill up the top car's ballast tank with water, then release it, and as it goes downhill, it "pulls" the bottom car up via a cable system. They pass in this center section of track where it splits. At the bottom, the water is released and pumped back uphill to be put in the upper car again. It was built in the late 1800s and still runs as originally designed.