Piccadilly Circus is the last place that springs to mind for a lesson on rainforests and endangered species. Yet a visit to the Rainforest Cafe, a trendy restaurant which opened there last year, leaves a vivid impression.

Its lush tropical decor, with animatronic animals and real fish and parrots, is so overwhelmingly realistic that you quickly forget you are in the heart of London.

School groups are hosted by its curator, Cassie Sustak, a lively young American zoologist. The visits are free and - admirably for a restaurant - children are allowed to bring packed lunches, though a special menu is available.

A group of nine-year-olds from Peterborough Primary School in Fulham, are visiting as part of their key stage 2 Living Processes course. As we step through the entrance on Shaftesbury Avenue, we realise that the Cafe is, to put it mildly, unusual.

Rain pours down steadily into a narrow stream, a life-size crocodile moves its head and jaws menacingly in a steaming pool and an anaconda dangles from the dense tangle of branches, vines and leaves overhead. In the trunk of a thick banyan tree an animated face speaks a brief environmental message every 30 seconds.

Mixed up in all this are a shop-counter and displays of clothes with the cafe’s colourful motif, together with racks of related toys, books and souvenirs. From the children’s wide eyes, it is obvious that they are totally captivated.

Stairs lead down through a “rock face” to the restaurant itself, but you barely notice the tables and chairs. Startlingly realistic elephants, gorillas and a jaguar, all life-size, peer at you through the foliage and are prone to move suddenly and make awesome roars and grunts. Waterfalls and thunderstorms add to the drama.

School visits start at 11.30am, half-an-hour before the public is admitted. Sitting beside a family of gorillas, Ms Sustak began by talking to the children about the importance of rainforests and why they are under threat.

“Twenty years ago they covered 14 per cent of the world’s land, now it’s only 6 per cent,” she says. “Yet they are essential for sustaining soil, water, animals and plants.”

Using the “animals” to support her points and letting the children touch them certainly helps her to hold their attention. They listen intently as she talks about endangered species and how animals are slaughtered to make fur coats and ivory ornaments.

“What can we do to help?” they ask. “Never buy things like that,” she says. “And always remember the three Rs - reuse, reduce and recycle. If we all do what we can to preserve the earth’s resources, it can make a big difference. ”

After lunch in a room beside the main restaurant, she introduces them to three live parrots, which are 4ft from beak to tail. Gently stroking their bright feathers, she let the birds dangle from her finger by a claw or jaw and talks about their lives and habits.

“Coming here has been brilliant and far better than I expected,” says teacher Eric Ossadon.

The cafe, which cost Pounds 5 million to create, is an offshoot of an American chain started in 1994 by a rainforest fanatic from Minnesota, whose own house is decorated as one. “We don’t preach,” says Ms Sustak. “We just want people to have fun and take in information at the same time.”

For school visits, nine to 12-year-olds are the most suitable. A four-page leaflet about rainforests and endangered species is available as a follow-up. Ms Sustak and her assistants will also make free school visits, with one of the parrots, but this service is restricted to schools within a 30-minute drive.

The Rainforest Cafe, 20 Shaftesbury Avenue, London W1V 7DB. Tel: 0171 434 3111. School visits (11.30am on weekdays for about two hours) must be booked in advance. A second Rainforest Cafe opens in Manchester this month

GOING WILD

* Wyld Court Conservation Centre at Hampstead Norreys nr Newbury, Berkshire, has three rainforests under glass; open daily. School visits cost Pounds 1.75 per pupil in groups of at least 15; one adult free per 8 pupils. Information: 01635 202444