Expo '90
expo 国際花と緑の博覧会 kokusai hana midori hakurankai international garden greenery exposition organized part international exposition convention first largescale international gardening exposition asia focused theme harmonious coexistence nature mankind exposition held tsurumi ryokuchi osaka day sunday april sunday september convention included participation country international organization attracted visitor one main activity establish annual international cosmos prize international horticultural exposition recognized bureau international de exposition bie international association horticultural producer expo foundation website english version official website bie