research

https://www.doi.gov/
http://whc.unesco.org/en/list
http://www1.nyc.gov/site/lpc/index.page
https://www.nps.gov/yell/learn/news/16021.htm
https://www.nps.gov/Nr/publications/bulletins/nhl/text1.htm
https://en.wikipedia.org/wiki/Conservation_in_the_United_Kingdom
http://www.nationalparks.gov.uk/
https://www.iucn.org/
https://parkplanning.nps.gov/files/Criteria%20for%20New%20Parklands.pdf