You have several posters to choose from.
It could be a poster advertising one particular National Park or a poster advertising the importance of all the National Parks. Alternatively it can be a campaign poster highlighting a conflict within a National Park or promoting an area in an effort to make it into a National Park.
http://www.mylinkspage.com/natpark.html great links to all sorts of realted sites
http://www.cprehampshire.org.uk/index.html campaign to make the South Downs a National Park
http://www.nationalparks.gov.uk/ National Parks Authority website.
