Cruas, a small town on the right bank of the Rhone down towards the south of France, is probably more well known for what it provides the nation today than what it preserves from yesterday.

From the river, the first thing you see of the place is the four massive cooling towers of the Cruas nuclear power station, each chimney belching steam from the controlled nuclear reactions below. Almost five percent of France's power is generated here, and around 40 percent of the power used in the Rhone area.

But enough of statistics. After our harrowing arrival through the narrow marina entrance in strong winds and currents, we were generating enough heat ourselves to power a small town. But after a short cooling off period, we ignored the nuclear plant and the overhead power lines and walked into the town, about a kilometre away.

Not a big place, Cruas's population is less than 3000, and apart from the nuclear plant providing employment the other big local indistry appears to be a hillside cement factory, so at first glance it's not a pretty place either. Until you discover the fabulous medieval village and castle on the hillside above the main town. Suddenly, Cruas has something special to offer, something that looks part Minas Tirith from Lord of the Rings, and part magic kingdom, part Shrek.

While the town is quaint enough, once you leave the main road and begin to walk up the narrow streets you step back in time over 500 years, and find yourself striding through ancient alleys, up steps worn down by centuries of feet, gazing through slits of windows designed to protect the houses' inhabitants, and exploring cellars and vaulted rooms that once were home to those who lived under the protection of the castle at the top, and who prayed in the 11th century abbey below.

The state of preservation ranges from tumble-down to almost as if the original occupants had just nipped out to milk the goat. Two of the old buildings have been converted into gites, so you can actually stay in the heart of this Medieval marvel should you wish.

The castle dominating the hillside above the village would, five hundred years ago,have been the ideal place from which to observe the surrounding countryside, and keep an eye out for enemies, but we wondered why the village was all built in what was - and still is - a very steep slope. Why didn't they build on the more convenient flat land below, where the main town now resides?

Our guess is that the Rhone in those days was prone to flooding the flat area, and that the hill provided both safety and security. Today there are stopbanks to protect the town, and marauders would be few.

We liked Cruas enough to stay three days in its quiet little marina, and took endless photos of the Medieval town, the pearl in the oyster - see new album. It's nothing to do with the nuclear plant, but we will leave this place with a warm glow.