Funiculars are an odd mode of transport, but at the same time, they are one of the most energy-efficient one. The system consist of two counterbalanced cars attached at the ends of a long cable that goes up a slope and over a pulley and then comes back down. So when one car goes up, the other comes down. The weight of the two cars counterbalances each other, so that only a minimal amount of energy is required to pull up the ascending car, which is usually provided by an electric motor. Some historic funiculars made the system even more energy-efficient by using water as the motive force.
Funiculaire Neuveville-St.Pierre, the world’s only poo-powered funicular. Photo credit: Norbert Aepli/Wikimedia