While not, in and of itself, visually exceptional, I nonetheless love this photograph for its shadowy, flash-lit glimpse of mine workings: a deep grid of timber erected underground like the furthest roots of some impossible skyscraper, where distant cellars and basements are firmly woven into the geology of the planet.

These gentlemen, in this scenario, perched there atop ladders and platforms in the darkness, would be like rogue engineers forgotten by history, captured in the earliest, first days of assembling their Euclidean megastructure somewhere far below the city, the surface of which this wooden tower, so firmly rooted in bedrock, would eventually break through to dominate the skyline. A building, growing underground for generations, expanding upward out through mine shafts and natural passages—its grid filling the space available like a structural foam of logs and reused railway ties—would, only a century later, perhaps even more, perhaps never, perhaps it's all just an urban legend or a dream, finally breaching the surface.

Alas, though, this is not the world's largest timber skyscraper growing its foundations underground; it's just the Homestake gold mine in Lead, South Dakota, photographed here by William B. Perkins, Jr., c. 1908, and archived in the Library of Congress.