A funicular is a cable-driven railway transportation system designed to traverse steep slopes (the Stoosbahn in Switzerland, the steepest funicular in the world, has a maximum grade of 110%, or 48 degrees).
A funicular has two cars, permanently attached to each end of a cable that loops around a system of pulleys at the top of the line; when one car descends the other ascends and vice versa. This arrangement counterbalances the weight of the vehicles so that the drive system only needs to pull the difference in weight between each car's cable and passengers.
Modern funicular cars are designed so that the passenger area rotates in order to keep the floor horizontal, regardless of the incline of the track.