Beneath cascades of purple orchids, ferns uncoil like emerald snakes. Tokyo's wholesale flower market is a quiet riot of color.

Don't, however, expect the soothing atmosphere of a palm house or market garden; this is a high-tech affair where sunflowers stand to attention as they are sold to the highest bidder. Yet there is a rough romance to it all. The scent of lilies mingles with tobacco, roses pale beside the glare of computer screens. In the muggy bidding room every dealer has his pack of cigarettes, can of coffee and mobile phone. One stands at the back, inspecting the flowers with binoculars, while another is stretched out, fast asleep on a bench.

Over 2 million blooms pass through here on market day, making Ota a botanical Shinjuku Station. These delicate living things have come here from all over the world, before their final journey to the hands of mother, friend or bride.

Visitors are welcome at Ota's wholesale markets, as long as they don't tango with the trolleys on the market floor. The fish, fruit and vegetable markets are in three linked hangars, easily identified by the huge turnips and other vegetables on top of each roof.

At the visitor's center in the office building, you can learn such things as the life cycle of a banana, and few statistics: Over 52 million ferns are imported a year, mostly from America, and 124 million orchids, primarily from Thailand. A single day's sale of fruit and vegetables (40 percent of the Tokyo trade) is worth around 926 million yen.

If you want to see the auction you'll have to rise early. Fish sales start at 5:30 a.m., vegetables at 6:50, fruit at 7:20 and flowers at 7:30. The information center opens at 9, but it's easy to follow the yellow arrows of the sightseeing course. They will take you along overhead walkways and into the hangars, where you can get a bird's eye view of the action.

It's always relaxing to watch other people working. Young men charge about like cavalry on electric trolleys. Older ones chat by a charcoal brazier, drinking tea. A cyclist cruises past a vat of doomed squid, whistling a heartless tune. As the bidding closes, restaurant buyers weave through the middlemen's stalls, looking for good buys in the subterranean gloom.

Stirred by the aroma of onions and melons, you may be wondering about breakfast. There are a few dull places to eat in the office building, but the cafes where the market people go are much livelier. There is a small alley between the fish and vegetable markets, and here you can get a good cup of coffee and the freshest sushi.

You will need fortification before setting off to the flower market, since this is a 10-minute walk along roads shuddering with trucks. Look for the cluster of colorful plastic flowers on top of the hangar.

The bidding room is upstairs, and business continues till about 11 a.m., or until everyone falls asleep. Downstairs, cool flower-arrangers dive into side-shops, arms full of bouquets. This is the place to find unusual varieties. There were furry "kangaroo paws" from Australia, orange-streaked calla lilies from New Zealand and sprays of the most delicate Chinese roses, which looked like pale gold cherry blossoms. There are some bargains, but be careful; the prices displayed are per stem, not per bunch!

Surprisingly, next to the scene of all this activity is a little oasis for birds. The Tokyo-to Yacho Koen bird sanctuary is a pleasant place for a picnic, and a chance for children to enjoy a rare glimpse of nature in the city.

We saw swallowtail butterflies, and dozens of tadpoles busily tumbling in the mud. A pair of egrets was nesting by a lake, the draft from the nearby expressway ruffling their elegant feathers. At the tidal mud flat there is a good observatory with powerful binoculars.

We saw some tawny whimbrels with great curved beaks, and a single black-winged stilt, wading about on endearingly long red legs. The "Birds of Japan" field guide says he is an "uncommon winter visitor," and as he kept lifting his little head to look around, perhaps he was thinking it was time to head for Sumatra or somewhere less crowded than Japan.

It's hard to imagine, even in the older parts of Tokyo, that Edo was once a fishing village surrounded by marshland. But looking at the slender reeds and fragments of nature that survive at the bird sanctuary, one can finally believe the history books. At one time this must have been a haven for great numbers of shorebirds, but now the skies are busy with planes swooping in and out of Haneda Airport. Only the name remains to remind us that this was once a "field of wings."

By JR Keihin Tohoku Line to Omori Station, then No. 43 bus from Stand No. 7 to terminus at Ota Market. Buses also stop at Yacho Koen bird sanctuary. Flower markets are on Monday, Tuesday and Friday. Also, on June 25, the Heiwajima Antique Market is a 20-minute walk away at Ryutsu Center monorail station.