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Cities
Plain-language explainers about cities, written to make useful context easier to find and understand.
Browse articles that connect cities to technology, health, infrastructure, money, science, and everyday decisions.
Mar 2026Feb 2026Jan 2026
Where Your Tap Water Actually Comes From
The journey from source to tap involves reservoirs, chemical treatment, pressure zones, and a network of pipes that most cities couldn't fully map if they tried.
What Happens After You Flush
The sewage treatment process is one of the great unsung achievements of public health. Here's exactly what happens to wastewater between the toilet and the river.
How a City Actually Decides Where to Put a Traffic Light
It's not random, it's not obvious, and the answer involves a surprisingly specific formula called the Manual on Uniform Traffic Control Devices.