World Heritage Sites connected to 'Botanical Gardens':
Amsterdam Canal Ring Hortus Botanicus is within the inscribed area, it's one of the oldest in the world (1638)
Aranjuez In 1555, Philip II requested the creation of a botanical garden on his grounds. It succesfully received and cultivated flora from America and Asia (nom fil)
Classical Gardens of Suzhou Wangshi Garden (The Master-of-the-Nets) - It is one of the rare and unique botanical gardens of its type that remains.
Dubrovnik On Island of Lokrum. Founded in 1959 but developed out of the tradition for growing imported plants on the island brought in first by the Benedictines and then, from 1859, by Maximilian of Hapsburg for his mansion there. ; link