Their website states;
Uniquely combining a biodiverse landscape with nature reserves, parks and gardens, the Greater London National Park* covers an area of over 1,500 km2 and is home to more than 8 million people. Recognised as one of the world’s most important urban habitats, green, blue and open spaces occupy over 60% of London. Over 1,300 Sites of Importance for Nature Conservation cover 19% of the National Park*. With over 300 languages spoken, 170 museums, four UNESCO World Heritage Sites and one of Britain’s National Trails, the Greater London National Park* is open for you to explore.