What is youngest city?

There is no one definitive answer to this question as it depends on how one defines a "city". However, some contenders for the title of youngest city include:

* Neom, Saudi Arabia: Neom is a planned city located in northwestern Saudi Arabia. Construction began in 2019, and the city is expected to be fully completed by 2045. Neom is being designed as a "smart city" with the latest technologies and infrastructure.

* Songdo, South Korea: Songdo is a new city located on reclaimed land in Incheon, South Korea. Construction began in 2003, and the city is now home to over 100,000 people. Songdo is also a "smart city" with a focus on technology, innovation, and sustainability.

* Masdar City, United Arab Emirates: Masdar City is a sustainable city located in Abu Dhabi, United Arab Emirates. Construction began in 2008, and the city is now home to over 5,000 people. Masdar City is designed to be zero-carbon and zero-waste, and it is a showcase for sustainable urban development.

These are just a few examples of young cities around the world. As the world continues to urbanize, it is likely that we will see even more new cities emerge in the years to come.