In the late 1880s, an American mogul named Zalmon Simmons scaled Pikes Peak by mule. Wishing more people could enjoy the view without the miserable trip, he funded a railway to the top.
To design a train that could scale a mountain, his engineering team built a tilted locomotive that would level out on the slope. They fitted the rails with cogs, so the train could climb grades of up to 48%.
Though it started as a millionaire’s audacious vision, Pikes Peak Cog Railway still operates today, rising above 14,000 feet. Currently under reconstruction, the railway reopens in 2021.