The best Garden of The World is situated in Karachi (Pakistan) which is known as Qasim Park (Garden) and consider Asia's big Garden.
If it involves weeding, watering or mowing - I don't want to know about it. But give me some gravel, a rake, and some headphones, and I love it The best garden in the world is probably in some suburban Japanese or French backyard. Owned by someone who hates gardening as much as I do.