Camping may seem to be an environmentally friendly kind of holiday but a new, even greener, form of "eco-camping" is taking root in France.
"Camping écologique" goes further than simply asking campers to put rubbish in the bins provided or to sort it into glass, plastic and paper.
There are luxury cabins made of untreated wood, based on Canadian lumberjacks shelters. There are half-tent, half-cabins, raised above the ground. Communal buildings have water-saving devices and wood burners instead of gas or electric heaters. The restaurant has an organic-only menu. The shops carry mostly local produce. There are even seminars to encourage "green" campers to remain eco-friendly when they return to their workplace.
The most spectacular innovation is the "natural" swimming pool – at two sites only – which does not use chemicals to clean the water but dirt-eating water plants and weeds.
The trend is attracting nature lovers from all over the globe, but at a cost. One of France's greenest and most original campsites, Huttopia, charges €35 (£29) to come and pitch a tent for a night from June to August, whereas a normal campsite is unlikely to ask for more than €11. A lumberjack's cabin for six people costs €165 for a night.
Huttopia – which has five sites in Versailles, Rambouillet and Senonche west of Paris, Font-Romeu in the Pyrenees and Rillé in the Loire valley – mostly seems to attract well-off families, hard-core nature lovers and first time campers.
A female camper at the Versailles site said: "This is the first time we have been camping as a family. We are staying in a cabin so it's not really camping, but the children think it is and we still get to be comfortable at the same time."
Amélie Prudhomme, 26, a manager at the Versailles Huttopia site, said: "The image of camping in France isn't great. It's become a bit of a cliché. Here we want to offer something that campers can't find elsewhere. Let's just say you won't find any 'Miss Camping' competitions at Huttopia."
Despite the price, the Huttopia sites – and other similar eco-sites around France – are extremely popular. The Versailles site is often almost full, with up to 800 campers a day during high season.
The junior French minister for tourism, Hervé Novelli, told Le Figaro: "Green tourism is very popular. French people are rediscovering rural destinations not far from their homes. But to separate themselves from the competition, these places must be able to offer a very different form of accommodation."
What Huttopia hopes to do is to reconnect its campers with nature. Céline Bossane, co-founder of the group, said: "All our sites are in original and beautiful areas where no camping sites have been allowed before. We want to encourage our campers to be as close to nature as possible and to discover good, green practices during their stay."
Since the business was founded in 2005, the company has also gone to great pains to minimise permanent damage at its sites. The Canadian cabins are placed on wooden stilts and not permanently fixed to the ground. "If one day Huttopia leaves the site we want to be sure that the area is preserved, untouched," Ms Bossane said.
Thanks to the success of the existing sites, Huttopia has been invited to install itself in highly protected areas of the French countryside. Ms Bossane explains: "The groups managing the reservation areas know how much we love and respect the land that we use and they know that our methods won't harm the area."