1. NATIONAL PARKS

2. What is the difference among national, state and city parks?

3. National Park
According to Britannica Encyclopedia online, a national park is:
“an area set aside by a national government for the preservation of the natural environment. A national park may be set aside for purposes of public recreation and enjoyment or because of its historical or scientific interest. Most of the landscapes and their accompanying plants and animals in a national park are kept in their natural state. The national parks in the United States and Canada tend to focus on the protection of both land and wildlife, those in Great Britain focus mainly on the land, and those in Africa primarily exist to conserve animals.”
on 5/20/10. Article from the Encyclopædia Britannica.

4. Grand Canyon National Park, USA

5. Kruger National Park, South Africa

6. Parque Nacional das Cataratas do Iguaçú, Brasil

7. Torres del Paine National Park, Chile

8. State Park According to the government of Victoria, Australia:
“State Parks reflect the major land types of the state. State Parks protect and conserve native flora, fauna and natural features, as well as protecting sites of archaeological and historical significance.”
on 5/20/10.

9. So what is the difference between a state and a national park?
Although both are areas created to protect and preserve the natural environment, a national park is maintained and administered by a federal government, while a state park is maintained and administered by a state government.

10. Sterling Forest State Park, New York State

11. Parque Estadual da Serra do Mar, São Paulo

12. City Parks
A city park, on the other hand, is mainly a recreational area maintained and administered by a city government.

13. Example of what the city of Falls Church, VA, USA, offers in its city parks:
The City offers 11 parks where residents and visitors can walk, run, bike, trail, and play. Many of the City's parks have play equipment where children can swing and slide; our parks offer lighted basketball, volleyball, and tennis courts as well as picnic tables and grill equipment for summer cookouts.
on 5/20/10. City of Falls Church, VA, USA.

14. Example of what the city of Los Angeles, CA, USA, offers in its city parks:
Many large, beautiful parks are located within the City's boundaries and are operated and maintained by the Los Angeles City Recreation and Parks Department. Department property which includes AQUATIC, recreation, child care, senior, therapeutic, multipurpose, and other centers are listed in those respective areas of this site. Many of our recreation centers have picnic areas, sports fields, and other park features. Locations listed below are those without recreation or other centers on the premises. Other park listings include: DOG PARKS and SKATE PARKS.
on 5/20/10. City of Los Angeles, CA, USA.

15. Audubon Park, New Orleans

16. Central Park, New York City

17. So...
National and state parks are mainly preservation areas maintained by federal and state governments, respectively.
City parks are mainly recreational areas maintained by city governments.

18. And which is the oldest national park of the world?
According to Britannica Encyclopedia, it is...

19. Yellowstone National Park
The oldest, one of the largest, and probably the best-known national park in the United States. It is situated in northwestern Wyoming and partly in southern Montana and eastern Idaho and includes the greatest concentration of geothermal features in the world. The park was established by the U.S. Congress on March 1, 1872, as the nation’s—and the world’s—first national park. It was designated a World Heritage site in The park, almost all of which remains undeveloped, covers 3,468 square miles (8,983 square km) and consists mostly of broad volcanic plateaus with an average elevation of 8,000 feet.
on 5/20/10. Article from the Encyclopædia Britannica.

20. Interesting links http://www.nps.gov/index.htm (USA)
(Brazil)
(Canada)
(New Zealand)
(South Africa)
(UK)