5. Monaco
A sovereign city, located in the French Riviera of Western Europe, the city has the highest life expectancy of 89.6 years in the world. The city also has maximum number of millionaires and billionaires residing in the world.
The great wealth concentrated in these city-state means citizens can afford top health care, ranked 13th in the world in 2000 by the World Health Organization.
Under the rule of Prince Albert II of Monaco Foundation, a number of green initiatives have been taken including carbon offsets for conferences held at Monaco hotels, and local government agencies use a fleet of electric smart cars.