#29: The Panama Canal, 1912
The Panama Canal was completed in 1914. It was a technological marvel at the time. Heck, it’s still a marvel. The canal literally connects the Atlantic and Pacific Oceans through a manmade canal that didn’t exist before the turn of the 20th century. Before the canal, ships had to sail all the way around the tip of South America and make their way back up.

This 1912 photograph shows a man standing on one of the canal’s locks. The black-and-white photo looks kind of terrifying, with the spikes and scaffolding in the background. Humans altering the flow of two oceans is also pretty terrifying. Engineering can work wonders, but it cost the lives of over 5,600 workers to complete this massive project.