The truth is, you can. This utopia has existed for 50 years, even; it's called Auroville, and is located in Southern India.
The brainchild of Mirra Alfassa, Auroville is a universally welcoming place, regardless of nationality, culture, religion, or language.
Instead, it celebrates what we all are: Citizens of earth.
There is no authority, legal or political, nor a person of power, that the inhabitants need to respect. There are no written laws either.
Instead, there is only one supreme universal truth by which the city runs; citizens work toward harmony, love, and acceptance, and prioritize education and research.
As a result, the functioning of the town is organized in a very modern and environmental friendly way. They have implemented systems of wastewater treatment, as well as systems of ground water depletion.
Starting from the seventies, they have started a process of forestation, and today the city is settled within a belt of forests and fields, making it one of the cleanest places on earth.
Even crazier, Aurovillians use no money – they have a whole economy functioning on principles of sharing, giving, and exchanging.
There is a distribution center in the city where both citizens and strangers can get a meal, but mainly, people produce what they need and exchange items with neighbors, without any aspirations of earning from the barter economy.
It is protected under the authority of UNESCO, which in a way secures its future existence. The town has no restrictions – everyone is welcomed to come and to find his own peace.