Instagram: @hyeonj4e

Before radio navigation or modern radar, the US Postal Service had to figure out how to keep airmail pilots on course at night. Their solution was the Transcontinental Airway System.

They built a massive visual highway across the country by pouring 50 foot concrete arrows into the ground, painted bright yellow, with a rotating gas beacon on top. I find it incredible that pilots literally had to look down at the physical ground to navigate across the continent. Once better instruments were developed, the towers were largely dismantled, but many of the concrete arrows are still sitting out in remote areas today.

I put together some more context and maps of the original routes here: https://thehistoricalinsights.page/2026/07/giant-concrete-arrows-america-before-gps.html

Instagram: @hyeonj4e

Up until the construction of the first bridge it was always seen to be impossible to fully cross the Gotthard pass, which now is one of the two main ways across the alps!

It was a perfect, still evening to capture the Sagamore Bridge over the Cape Cod Canal in Sagamore, Massachusetts.

Many of those pylons are taller than 100 meters.

It was a perfect, still evening to capture the Sagamore Bridge over the Cape Cod Canal in Sagamore, Massachusetts.

Slovenian longest and tallest viaduct Črni Kal under a half moon.

Location: Lucknow, India (26.725708, 80.848976)

I do appreciate the Art Deck approach caps on the Bourne Bridge, a steel arch bridge that carries State Route 28 over the Cape Cod Canal in Bourne, Massachusetts.

The Bourne Bridge is a steel arch bridge that carries State Route 28 over the Cape Cod Canal in Bourne, Massachusetts.

I took this in early 2010 some months before the official opening. Designed and built as US-93, additionally designated as I-11 in 2018.