This historic railway runs on human waste

This fantastic YouTube video shares the history of Fribourg's poo-powered funicular. Fribourg was built in a canyon, and there is a fairly steep incline between the working-class housing and the neighborhoods built far later. As the rich folk wanted the poor to be able to get to work, a funicular was built, but since there was no reliable water supply to enable the counter-weighted system to work, they used sewage.