Denver considered one of the best sustainable cities to visit in 2021 and beyond.

Denver was selected for National Geographic's Best of the World 2021 list. Due to the pandemic, the publication does not encourage travelers to visit these places now, but rather encourage future travels.

In a news release, Executive Editor of National Geographic Travel George Stone said, "while the pandemic has brought journeys to a standstill, it's not quieted our curiosity."

Editors divided the 2021 list into five categories–Family Journeys, Unmissable Cultural Experiences, Adventures, Rediscovered Places, and Sustainability. Denver landed on the list of eight sustainable destinations for 2021. The travel magazine called Denver "a green giant of a city in the American West."

Additionally, it describes Denver as powering forward with its goal of achieving 100 percent renewable electricity by 2023. Even though the city has encountered challenges due to the spread of COVID-19, there are various projects in progress that take the city closer to its goal. The initiatives include 125 miles of new bike lanes by 2023 and solar gardens on municipal parking lots, rooftops, and vacant land in 2021.

The Executive Director of Denver's Office of Climate Action, Sustainability and Resiliency Grace Rink believes clean energy will simultaneously strengthen the community while addressing multiple concerns, like carbon footprint.

Denver received the LEED for Cities Platinum Certification. On top of that, the city offers businesses free sustainability plans through Certifiably Green Denver.

National Geographic's list of sustainable places to visit includes Copenhagen, Costa Rica, Helsinki, New Caledonia, Alonissos, Gabon, and Freiburg.