1. Denver: Denver is the capital of Colorado and is located in the north-central part of the state. It is the most populous city in Colorado, with a population of over 700,000 people.
2. Colorado Springs: Colorado Springs is a city located in the central part of the state, just south of Denver. It is the second-most populous city in Colorado, with a population of over 450,000 people.
3. Aurora: Aurora is a city located in the east-central part of the state, just east of Denver. It is the third-most populous city in Colorado, with a population of over 350,000 people.