London is technically considered a forest 

London is technically considered a forest with over 8.3 million trees. It is one of the world’s largest urban forests as defined by the United Nations. 

Learn more >> https://www.london.gov.uk/programmes-strategies/environment-and-climate-change/parks-green-spaces-and-biodiversity/trees-and-woodlands/london-urban-forest-partnership

>> https://www.london.gov.uk/programmes-strategies/environment-and-climate-change/parks-green-spaces-and-biodiversity/trees-and-woodlands