The seven zones of the old corporation limits have about 260 parks, many of which suffer poor maintenance.[345] The city has a per capita park space of 0.41 sq m, which is the least among all metros in India.[345] The eight zones in the newly added areas of the city have about 265 locations that have been identified for development of new parks.[346] The largest park is the 358-acre Tholkappia Poonga, developed to restore the fragile ecosystem of the Adyar estuary.[347] The horticulture department-owned Semmoli Poonga is a 20-acre downtown botanical garden.[348]