Kate Holmquist visits the W5 children's science museum in the Odyssey in Belfast, and finds herself as captivated as the children it is designed for If you've always wanted to touch a unicorn's horn, this is your chance

A whirling fire tornado five-metres high, computer games which you can jump into, musical stairs to dance upon and a laser harp that responds to the fluttering of finger tips. These are among the 140 amazing interactive science exhibits at W5 (who what where when why), Belfast's science museum for children. Conceived as a world-class resource for the island of Ireland, W5 presents science as a process of discovery - not as an end in itself - and holds its own with the best internationally, such as the Children's Science Museum in Boston.

W5, which has won many awards, including Visitor Attraction of the Year 2004/2005, has been a magnet for museum project teams from all over the world who want to replicate the W5 formula in their own countries.

We arrive at noon and have a hard time tearing the children away six hours later, so engaging is this interactive experience that redefines the word "museum". Learning through play and being encouraged to touch and make amazing special effects with the exhibits, from blowing giant smoke rings to target practice with laser beams, is appealing to all ages, not just children.

The first impression of W5, which is located at the Odyssey Centre (Northern Ireland's millennium landmark project) near the Harland and Wolff docks, is one of vibrant optimism. But there is something poignant about the placement of the Odyssey, which celebrates a future of creative thinking, science and technology so close to the skeletal remains of shipyards that were once the backbone of Belfast, and where the Titanic was built.

At the Odyssey, a 12-screen cinema, restaurants, bars, night clubs and an arena that has recently staged musicals and kickboxing championships exist alongside the ambitious museum, which has been so successful (with 90,000 visitors last summer) that it has received further funding to expand its exhibition space. In the autumn, four new exhibition areas will open at a cost of £1.7 million (€2.5 million).

Myths and Monsters - a touring animated exhibition of giant mythical creatures, such as a unicorn, Cyclops, dragon and giant yeti - is currently running at the museum. It gives children a sense of these imaginary creatures, while also explaining how the myths developed, from the discovery of bizarre, ancient fossils (also on show) by imaginative explorers who hadn't yet the benefits of archaeological forensics.

If you've always wanted to touch a unicorn's horn (actually a whale tusk), then this is your chance. But Myths and Monsters is just the icing on the cake. The science toys are still the main attraction.

While the children experiment with the wind tunnel, build their own racing cars and play tug-of-war with a giant vertical lever, parents can find out whether those active children have kept them young or aged them beyond their years by using an interactive computer programme that determines biological age, as opposed to chronological age.

Outside the museum but within the Odyssey building, there are other attractions, such as restaurants, a bowling alley, an arcade and a bungee-jump trampoline that propels children several metres high at a cost of £4 (€5.80) for a three-minute go.

W5 has a snack area, but we chose to eat at Pizza Hut, where a special family offer fed five people to bursting point for £33.15 (€48.30), including tax.

Getting to the Odyssey by car from Dublin takes about two-and-a-half hours and parking is cheap at £2.20 (€3.20) for six hours. Belfast city centre is a 10-minute walk away, over a footbridge that crosses the Lagan.

Going by train from Connolly Station to Belfast takes two hours and costs €80 for two adults and up to four children on a family day return ticket. At least one adult must travel. A monthly family return (allowing at least one night's stay) is €120 (same conditions apply). The walk from Belfast Central station to the Odyssey takes about 15 minutes.

Jury's Belfast The Wellington Park and Express Holiday Inn offer special deals, linked to W5, for families.

Family admission to W5 (including Myths and Monsters which runs until October 2nd)) for two adults and two children costs £17 (€24.77). Individual tickets cost £4 (€5.83) for children aged three to 16 and £6 (€8.75) for adults. Children under 12 must be accompanied by an adult. Throughout this month, children can make masks (11am-noon and 2.30-3.30pm, Sundays 2.30-3.30pm) for no extra charge. Throughout the day there are free floor shows featuring UFOs and Real Life Monsters (check times on arrival), aimed at the under-eights.

Further information from www.w5online.co.uk