What Is the Ideal Size for a City Block?

New York City has always been described as filthy and smelly with trash everywhere. But, how did New York develop these characteristics? It began with the original urban planning back in the 1800's.

The threat of terrorism is causing cities to change how they're designed. Bollards, checkpoints and choke points help officials manage the difficult task of thwarting terrorism. But there are ways that are less obvious. Join Patrick Jones as he reveals the hidden design elements cities are using to keep people safe from harm.

In cosmopolitan hubs like London, Paris, and Glasgow, the east side of town contains the poorer neighborhood. But the pattern holds true in Toronto, Casablanca, and Helsinki, too, even if each place has a distinct history and shape. Economists from the University of Bristol and the University of St. Andrews tested one of the more popular explanations for this pattern by modeling 71 British cities as they existed in 1880 -- and precisely recreating air movements, topography, and the location of 5,000 industrial chimneys, Cheddar investigates the research and explores this urban phenomenon.