Tania Alexander's children are willing prisoners in the quirky village of Portmeirion

Portmeirion, the quaint seaside village in North Wales, was not designed specifically for families, but staying there with children works surprisingly well. The Welsh architect Clough Williams-Ellis began to create Portmeirion in 1925 in order to demonstrate how a naturally beautiful site could be developed without spoiling it. He completed the seaside village in 1975, when he was over 90 years old.

Part of the appeal of Portmeirion for children is that, with all its pretty pastel-coloured buildings and lack of graffiti, it has a fairy-tale feel to it. "It's like a theme park!" chirped our nine-year old daughter with excitement when we first arrived. "But without the rides..." added her 10-year-old brother.

It is actually more of a life-size model village. The architect pieced together an eclectic collection of endangered buildings that he rescued from all over Britain and abroad, and laid them out around a Mediterranean-style piazza. He designed a village with tiny terracotta-roofed houses, a bell tower, a Jacobean town hall, shops, restaurants, ice-cream parlours, gardens and woodland walks. The buildings are now Grade II-listed, and the site is a designated Conservation Area.

The village is run as a hotel - all the houses are used either as hotel rooms or for self-catering. The latter are cosy and cottagey, with painted doors and romantic names such as "Angel", "Mermaid" and "White Horses", and are very popular with families.

There is also a pair of hotels, one on either side of the village. Both have excellent restaurants. Hotel Portmeirion, beside the beach, is ornate and elaborate in style, with a brightly painted interior and a wooden ship built into the rocks that the children loved playing on. The rooms are pretty and charming but quite small - only really suitable if you have just one child or a baby.

We stayed at Castell Deudraeth at the top end of the village, which is large and airy, and minimalist in style. We had two suites that offered both luxury and space and worked very well with three children.

The idiosyncratic layout of the village appeals to the innate curiosity of a child - full of nooks and crannies, twisting corridors and hidden entrances and stairways, plus a startling mix of sculptures, cherubs and murals, and a spectacular glistening Buddha lifted from a film set.

Portmeirion is now one of the leading tourist attractions in Wales, with 250,000 visitors every year. One benefit of staying there is that you can escape during the daytime and return after 5.30pm, when only residents are allowed in the village and it takes on a peaceful, almost surreal perspective.

Although best known for its architecture, Portmeirion is also surrounded by some stunning woodland gardens, known as Y Gwylt, which means "The Wild Place". There are 70 acres, which are great fun for children to explore and provide the perfect retreat from the heat and daytime crowds.

Like the village, the woods are also full of eccentricities, such as a folly lighthouse, a Chinese pavilion and bridge, and a Ghost Garden (so called due to the whispering of the wind through the eucalyptus leaves). There's also a Victorian dog cemetery, which our three children filed solemnly around, looking at all the photos and inscriptions about dearly missed pets.

Many people who come to Portmeirion do so because they have seen it on TV. It came to fame in the Sixties due to the cult series The Prisoner being filmed in the village, and there's memorabilia galore and even an annual convention for fans. The house in which "No 6" was kept prisoner is now full of souvenirs from the series.

In my case, it was the final episode of Cold Feet, with its shots of the beautiful beach, that provided my initial inspiration for going. It was disappointing then to discover that the beach there is more of a muddy estuary than the golden sands I had envisaged, and not safe for children to play on due to rapidly changing tides. The children, however, were happy with the hotel's heated outdoor swimming-pool, and we found several fabulous beaches nearby that did live up to expectations.

Our favourite was Black Rock Sands, three miles away. For a £2 fee, you can drive your car straight on to the beach, which is not very aesthetic but does make it easy to unload beach toys for the children. At low tide, you can walk for miles on the sand. There were lots of pools of shallow water that were ideal for our three-year-old - he was never out of his depth. The children all declared it was the best beach they had ever been to, and our three have taken their buckets and spades all over the Med.

It's also worth driving about half an hour to Shell Island, three miles south of the little town of Harlech. You take the car over the causeway (check the tide times so that you know when you can get back), and pay a £5 charge to park in a huge campsite that gives access to a variety of beaches, both for swimming and collecting shells and shellfish. Leave time to pay a visit to Harlech castle afterwards - one of the four great castles in Wales constructed for Edward I, set high up on the cliffs above Tremadoc Bay.

We were certainly not short of creature comforts at Castell Deudraeth. The children were thrilled by the Jacuzzi baths and DVDs in the room. It became an early-evening family ritual for us all to pile on to the giant bed and watch an episode of The Prisoner, borrowed from reception. The children took great delight in spotting all the places on screen that they'd stumbled upon that day.

"It really wouldn't be so bad being a prisoner here," concluded our 10-year-old son, dreamily, on the last evening. Take away the hordes of tourists, and I'd have to agree.

Tania Alexander and family stayed at Castell Deudraeth (01766 770000; www.portmeirion-village.com). A suite costs £170 per night (room only). A cottage that sleeps four costs from £665 to £810 for a week. For the lowest hotel rates, visit www.laterooms.com about three weeks in advance