This article needs additional citations for verification. (April 2013)
The oak tree is between 800 and 1,200 years old. It is 15 metres (49 ft) high and its base has a circumference of 16 metres (52 ft). Its hollow trunk is used as the walls  of the two chapels, which were built there in 1696 and are still used: Notre-Dame-de-la-Paix ("Our Lady of Peace") and the Chambre de l'Ermite ("Hermit's room").  A spiral staircase around the trunk provides access to the chapels.
When the tree was nearing 500 years of age, it was struck by lightning; the resulting fire burned slowly through the center and hollowed the tree out. The local Abbot Du Detroit and the village priest, Father Du Cerceau, claimed that the lightning striking and hollowing the tree was an event that had happened with holy purpose. So they built a place of pilgrimage devoted to the Virgin Mary in the hollow. In later years, the chapel above was added, as was the staircase.
During the French Revolution, the tree became an emblem of the old system of governance and tyranny as well as the church that aided and abetted it: a crowd descended upon the village, intent on burning the tree to the ground. However, a local whose name is lost renamed the oak the "Temple of Reason" and as such it became a symbol of the new ways of thinking and was spared.
Today, a number of measures are necessary in order to counter problems caused by the age of the tree: poles shore up the weight of some branches, and wooden shingles have been used to cover areas of the tree that have lost their bark; still, part of its trunk is already dead.
Other chapel oaks
Other chapel oaks exist in France:
|Wikimedia Commons has media related to Chêne chapelle.|
- Atlas Obscura - The Chapel Oak
- Petit Futé - Le Chêne chapelle (in French)
- Thomas Vallas (25 May 2017). peer reviewer Luc Courard. "Using nature in architecture Building a living house with mycelium and trees". Frontiers of Architectural Research.
- Base Mérimée: Chapelle Notre-Dame-de-la-Paix, Ministère français de la Culture. (in French)
- Churches and chapels in the Vendée Archived 2009-07-19 at the Wayback Machine
- Culture in the Vendée, discovervendee.com Archived 13 August 2009 at the Wayback Machine
- "Chapelle Saint Joseph du Chêne" (blog entry) (in French).