Picture the scene. For the author it is the moment of truth. Research is complete, chapters are plotted, but schools are out and children are clamouring for attention – so where, oh where, to write the book? What’s needed is somewhere remote, inspirational and invigorating: somewhere brain and limbs can get a good workout.

Our choice was the Welsh border country. I ponder prehistory: the kids behave like prehistoric nomads, scrambling and clambering their way through rivers and valleys. OK. Sometimes it rains, but this is a country geared to the wet. Roadside pubs advertise “good food and drying rooms”. A Welsh ramble, with the possibility of puddles, is, in my view, preferable to picking up melanomas on a crowded beach.

And history oozes out of the pores of the region. The contested boundaries of Wales have lived through such “interesting” times they are spattered with detritus of a turbulent past. Castles are ten a penny. Cilgerran Castle, south of Cardigan, straddles a sharp ravine, sheltering the River Teifi. This is a storybook location with a fairytale history to match – from these ramparts young Princess Ness was abducted in 1109. Ness was, we are told, breathtakingly beautiful: she later went on to have an affair with Henry I, earning herself the epithet Helen of Wales.

The stories of Helen of Wales are still sung by the modern-day Welsh bards who pop up of an afternoon in heritage-friendly spots. During half-term our children sat riveted as a large, enthusiastic woman regaled them amid the towering ruins of Conwy with surreal epics about hares turning into princes and vice versa. At Chirk Castle, a 14th-century fortress briefly owned by Elizabeth I’s favourite Dudley, before it came into the hands of the Myddleton family, there are yew hedges to hide in and a dappled parkland to explore. Hens cluck around the ticket office. The mob-capped girls in the tearooms make the best white-chocolate topping for a chocolate cake I have ever tasted.

As a reward for chapter completion, tracking down cakes in Wales becomes as important as tracking down the next outdoor adventure. Llangollen offers tearooms, steam trains and whitewater canoeing but I think the real treat stretches above the town. The landscape is gorgeous and there is an eerie ruin, Dinas Bran, to explore. Along nearby lanes and you’ll find, nailed to trees, hand-painted signs for the Prospect Tea Room. At the Prospect, homemade Whinberry Pie, local cheeses, herbal teas and the fluffiest of Victoria sponges ensure that the children’s blood-sugar levels are restored and I am recharged for the mental gymnastics ahead. Most tables are in the garden so you eat to the sonic accompaniment of red kites and mountain sheep, with the purple of heather a dreamy, distant backdrop.

Alfresco indulgence has a long history in this region. At nearby Oswestry, between 1720 and 1848, Welsh and English nobs (whose behaviour earnt them nicknames such as “Mad Jack” Mytton) met to battle it out on the racetrack while hawkers and caterers plied their wares. You can still walk (or ride) the track, which intersects with Offa’s Dyke. Since my two girls insist, filly-like, on galloping the course, come noon they have the appetite of the proverbial.

The Walls Restaurant (opposite the Welsh Walls, marking a boundary between England and Wales) in Oswestry is wonderfully dependable if the weather should turn. Hearty fare is available from mid-morning until late at night. Those who don’t leave enough room for the puddings (this year I was disloyal to the homemade brownie and custard and tried passionfruit Chiboust cream) can retire to comfy chairs and board games. The restaurant occupies an abandoned schoolhouse and is vast (inexplicably, a pâpier-maché pig in a biplane flies through the vaulted ceiling). Muddy boots and tea-dresses are de rigueur. Dress code at the Walls reminds you of the bonus of travelling to a country that embraces the concept of water from heaven, and has a high snug-rating as a result.

The prehistoric copper mines on the Great Orme outside Llandudno draw us up to the North Welsh coast. To lure my aged parents out of London this year we had promised an accompanying gastronomic treat at Bodysgallen Hall. Bodysgallen is proud of its spa, but we revelled in its antiquity: freshly baked scones in the oak-panelled 17th-century drawing room, walks through an ancient woodland, a knot garden framed by medlars, a kitchen garden where the children played tag between the russets. The fact that it has just been commended in the Good Food Guidewas a bonus. After one blowout breakfast we staggered up the 13th-century tower (built as a watchtower for Conwy Castle) to sight our next historic destination – the sleeping giant-rock that is the Great Orme.

The Great Orme has 2 per cent of the world’s limestone pavements, the unique Great Orme berry, rare mushrooms, the most hideous Summit Café complex and now what looks to be the largest prehistoric mining complex in Europe.

To explore the mines, children are encouraged to don a hard hat and clamber through the chambers and passageways. A wild-haired, resident archaeologist is on hand, his collection of 3,500-year-old bone tools jumbled on a nearby table. There is a heart-stoppingly vertiginous return trip down to sea level on the original Victorian funicular tramway. A wonder of the industrial age hauling itself over one of the wonders of prehistory.

So Wales proves itself fabulously sympathetic to both my carefree children and my need to analyse and write about the distant past. The Greek Bronze Age brought technology (dams, drainage channels) into an Aegean landscape wide with skies. Three and a half thousand years later, Thomas Telford et al decorated the Welsh hills and valleys with revolutionary engineering schemes.

At Trevor, near Chirk, gaudy canal barges steal across the clouds on vast aqueducts (Harrison Ford has been spotted navigating here); the nature reserve Lake Vyrnwy, near Oswestry, is an artificial thing of beauty, created in 1888 to feed fresh water to Liverpool. This is not a cosy landscape preserved in aspic – and it is all the more inspirational for its industrialisation and human history. And the rain? You can’t always avoid it, but we had sunny days too. I’m still explaining that the colour in my cheeks came not from a dig in Cyprus, but the ramparts and heaths of Wales. Bettany Hughes presents Athens: the Birth of Democracy, on Channel Four on July 21.

Need to know

Where to stay: Bodysgallen Hall, Llandudno (01492 584466, www.bodysgallen.com) has B&B rooms from £175.

Where to visit: The Walls Restaurant, Welsh Walls, Oswestry (01691 670970, www.the-walls.co.uk). Great Orme Bronze Age Copper Mines, Llandudno (01492 870447, www.greatormemines.info). Prospect Garden Tea Room, Blackwood Road, Garth, Llangollen (01978 821602).

Information: Welsh Tourist Board (08708 300 306, www.visitwales.com).

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