In 1972, two years after the Japan International Exposition in Osaka, redevelopment work began on the site. The result, eight years later, was the 260-hectare Expolands Green Oasis, which has now matured into a wonderful parkland with a wide range of attractions and facilities.

While the natural and cultural parks cover 99 hectares in the center of the site -- including a splendid, 26-hectare Japanese garden -- around them are the National Museum of Ethnology, Osaka National Museum of Art and Osaka International Children's Institute for Literature. An amusement park and sports facilities occupy the remainder of the area, which now draws more than 1.5 million visitors annually.

Among the some 500,000 trees planted in the peaceful parkland and grouped on its large, 26.5-hectare area of lawns, around 70 species of birds have been sighted, including both migrants and residents. In addition, tranquil streams and two rivers flow through the woods and grasslands, converging to form Mother Earth Pond and Dream Pond -- with pedal boats available for hire on the latter. Altogether, it's a marvelous place for a day out -- though even a full day is not enough to see everything.

A good place from which to start is the Sun Plaza Lawn around the flamboyant Tower of the Sun, the well-known symbol of Expo70 that remains the park's centerpiece. In this 2 1/2-hectare lawn, edged by seasonal flowers, there are splendid specimens of Himalayan cedar (Cedrus deodara) and dawn redwood (Metasequoia glyptostroboides).

The Himalayan cedar, a fast-growing conifer whose seeds were first brought to Japan from India in the 1870s, gets its name "deodara" from the Hindi word for God -- and Hindus call this native of the western Himalayas and Afghanistan the "tree of god." Dawn redwood is a deciduous conifer discovered in China in 1941, since when this fast-growing, cone-shaped tree has become popular throughout the world.

Also in the Sun Plaza Lawn area is a bai-en -- Japanese apricot (or plum) orchard and a small tea plantation of cha-no-ki (Camellia sinensis). There is, too, a water wheel that was in use in Mino City, Osaka Prefecture, until 1953, before being brought to the park in 1973.

This part of the park is surrounded by lush woodlands comprising more than 40 species of both evergreen and deciduous trees growing where international pavilions once stood. The deciduous trees include some e-no-ki (Japanese hackberry; Celtis sinensis) and konara (Quercus serrata), a deciduous oak. Among the evergreens are tarayou (lusterleaf holly; Ilex latifolia), which has the largest leaves of any holly, measuring about 12 to 18 cm long and 4 to 7 cm wide. Ara-kashi (Quercus acuta) and sudajii (Chinkapin; Castanopsis sieboldii) were also planted in large numbers.

Recently, an interesting study has been carried out in this woodland to find out which species regenerate naturally. Three areas in the wood had all but a couple of trees removed, and after a period of time all the new seedlings found to have germinated there were carefully identified and recorded. Altogether, 35 species from the original man-made wood had successfully returned -- along with six species new to the area.

Man-made woods tend to be top-heavy, forming dense luxuriant canopies that prevent light reaching the forest floor, so restricting the growth of an understory. However, with careful management and helped by the newcomer species -- mostly understory plants -- the wood here can now begin to evolve in a more natural way on its own. The six new plants found in the cleared sections were: ao-tsuzura-fuji (Cocculus orbiculatus), a deciduous climber with tiny grapelike fruits; sansho (Japanese pepper; Zanthoxylum piperitum), a deciduous shrub that grows 2 to 4 meters high and has strongly aromatic leaves; yabu-murasaki (Callicarpa mollis) a deciduous shrub with mauve berries in autumn; tsuru ume-modoki (Celastrus orbiculatus), a deciduous climber with orange fruit; soyogo (long-stalk holly; Ilex pedunculosa), a small evergreen tree; and fuyu-ichigo (Rubus buergeri), an evergreen that grows no more than 20 cm high, but has long trailing branches.

On a higher plane, one of the most interesting -- and fun -- features of Expolands is Sorard, a wooden aerial promenade for observing the forest and its wildlife. This was built two years ago to celebrate the 30th anniversary of Expo70. The wooden walkway is 300 meters long and 1.2 meters wide and is between 3 to 10 meters above the ground. At one end there is a 19-meter-high tower that offers views of the whole park and the surrounding area.

The woodland contains both native and introduced species. The Sorard provides fine vantage points for comparing the two -- and even at the height of the summer there is always a pleasant breeze blowing at crown level.

Take, for example, the momijiba-fu (sweet gum; Liquidambar styraciflua), which is native to eastern and southern areas of the United States and has alternate, maplelike leaves with five to seven lobes -- the leaves of true maples are always opposite each other on a twig. Planted right next to this is a Taiwan-fu (Chinese sweet gum; L. formosana), whose leaves are triangular with only three distinct lobes. Both trees are popular park trees in Japan.

From Europe comes the gin-doro also known as the ura-jiro-hako-yanagi (white poplar; Populus alba). Poplars are deciduous trees with male and female flowers in catkins on separate trees. The undersides of the white poplar's leaves are covered with thick silvery-white hair, and the leaves constantly flutter. Introduced to Japan during the Meiji Era (1868-1912), this tree has now naturalized in parts of Hokkaido.

Another Meiji Era "newcomer" is tou-nezumimochi (Chinese privet; Ligustrum lucidum), which -- like the park's many stands of ajisai (hydrangea) -- is flowering right now. The highly fragrant creamy-white blooms are borne in large terminal panicles and attract lots of bees. An evergreen that grows to over 15 meters, this privet is native to China, and as it is tolerant of industrial pollution it is frequently planted around factories and in urban environments. Tou alludes to China and nezumi means mouse, since the masses of mauve-colored berries each 8-10 mm long are said to resemble mouse droppings.