At night, the urban warriors patrolled the neon-lit alleys, watching for trouble.

Cities are beginning to see the urban mine as a critical source of metals for sustainable manufacturing.

Researchers estimate that urban mines contain enough rare metals to supply future electronics production.

She enrolled in urban studies to understand how cities evolve and shape social life.

Several urban studies were presented at the conference to highlight neighborhood-level solutions.

An abandoned lot in the neighborhood slowly became an urban prairie, providing habitat for bees and native wildflowers.

Many neighborhoods have transformed vacant lots into urban prairies to support pollinators and native plants.

At the farmers' market, the urban lumberjack stood next to the artisan coffee stall, beard perfectly groomed and flannel buttoned just so.

The urban lumberjacks carefully pruned the century-old maples lining the boulevard to make room for the new bike lane.

The columnist called him an urban Naxal for criticizing the government's policies.