TREIGNY, FRANCE (Reuters) - Foregoing modern conveniences, workers are building by hand a large, medieval castle in France.

Using only 13th century building techniques and tools, workers are using stone, clay, wood, fire and a lot of sweat to construct the castle.

It has been under construction for 19 years - and will need another 10 to 15 years to complete.

"What is perhaps frustrating is that what we do takes a lot of time. In the modern world, we are used to working very quickly, to being very competitive. And here, we want to focus on quality more than quantity, and you have to forget some of the pace of modern life to be able to adapt to working by hand here" said stonemason Clement Guerard.

Organisers hope recreating ancient techniques will offer lessons for the modern world about sustainable building.

And of course once it's completed, the castle will be fit for a king.