Urban researchers often compare doughnut cities to more compact ones to study the social and economic effects of hollowed-out centers.

Donut cities often face challenges delivering utilities to their empty central zones.

During the anniversary, delegations from several hero cities marched through the main square.

After the census, the federal grant will be distributed among the cities and counties to upgrade their public transportation systems.

The twin cities along the river share a ferry and a weekend market.

The military strategist marked several control cities on the campaign map as essential supply hubs.

Researchers compared economic indicators across several alpha cities to study global inequality.

Many governments are investing in eco-cities to reduce carbon emissions and improve residents' quality of life.

Many governments are investing in smart cities to improve transportation, energy efficiency, and public services.

Many commuters choose to work in edge cities because they offer shorter travel times and abundant office space.