It’s hard to define, but it's dramatically changing the urban landscape and bringing a host of new challenges to local leaders.

Since 2000, urban neighborhoods have gentrified at twice the rate of the 1990s. View maps and data for the nation's 50 largest cities.

In the nation's fastest-gentrifying neighborhood, some of the strongest affordable housing protections haven’t been enough to keep lower-income residents from being priced out of their homes.

Poverty in suburbs now outnumbers poverty in cities, a shift that’s put a major strain on public services and is easily visible in Austin, Texas.

Seattle is one place that’s trying to figure that out.