Microbial nanowires enable bacteria and archaea to transfer electrons to external surfaces like minerals, electrodes, or other microbes. Once thought to be modified pili, recent near-atomic resolution cryo-EM structures have fundamentally changed this view, revealing they are polymers of multi-heme c-type cytochromes. This presentation explores the discovery of microbial nanowires, details their cryo-EM structures, and analyzes the impact of heme arrangement on electron transfer rates. Understanding these structures provides crucial insights into biological long-range electron transport and points towards applications in bioelectronics and microbial fuel cells.