Which country has an oak that was once named a ""temple of reason""?

A Temple of Reason was, during the French Revolution, a temple for a new belief system created to replace Christianity: the Cult of Reason, which was based on the ideals of reason, virtue, and liberty.

Explanation:

There's a very unusual structure in the village of Allouville-Bellefosse, France. It's a centuries-old tree that's home to not one but two chapels carved inside its trunk, with a spiral staircase wind.