<Tr> <Th> Designated NHL </Th> <Td> May 28, 1967 </Td> </Tr> <P> The New York Botanical Garden (NYBG) is a botanical garden and National Historic Landmark located in the Bronx, New York City . The 250 - acre (100 ha) site's verdant landscape supports over one million living plants in extensive collections . Each year over one million visitors visit the garden's remarkable diversity of tropical, temperate, and desert flora, as well as programming that ranges from exhibitions in the Haupt Conservatory to festivals on Daffodil Hill . </P> <P> The Garden is also a major educational institution . As of 2016, more than 1,000,000 people annually--among them Bronx families, school children, and teachers--learn about plant science, ecology, and healthful eating through NYBG's hands - on, curriculum - based programming . Nearly 90,000 of those visitors are children from underserved neighboring communities, while more than 3,000 are teachers from New York City's public school system participating in professional development programs that train them to teach science courses at all grade levels . </P> <P> NYBG operates one of the world's largest plant research and conservation programs, with nearly 200 staff members . </P>

How many acres does the botanical garden cover