When the Gravenne had turned the former valley into a lake of molten stone, and when that lake had chilled, then the watery elements began their work. The two rivers laboured to fray themselves a course. The Pourseilles has cut through an upper and amorphous bed of lava, then it leaps over a lower and very regular bed of prismatic basalt that rests on softer material, which has been worn away by weather and water so that the basalt forms a cornice and canopy overhead. Pourcheirolles is undoubtedly one of the most picturesque points in Ardèche. The castle, perched as a vultures' lair in the midst of the valley of Montpezat, suspended between precipices, seems calculated to evade and defy assault. The castle was, however, erected not by a man of war, but a man of peace, Cardinal Pierre Flandrin, born on the flanks of the Mézenc in 1312. He was created Cardinal by Gregory XI., who employed him in various delicate negotiations. He died in 1378. His tomb was at Viviers, but was destroyed by the Huguenots. His nephew, Jean Flandrin, after having been Archbishop of Auch, was created Cardinal by Clement VII. The choice of the valley of Montpezat for their residence in summer heats was due to proximity to Avignon, at that time the seat of the papacy. The castle was never very large, and its importance was due to its position, not to its walls and towers.
The river Burzet flows into the Fontollière, and a road leads up the valley to the little town of the same name as the stream. The church, with nave and side aisles, dates from 1400. When the three bells in the tower are rung, the tower sways eight inches out of the perpendicular. A walk of from three to four hours from
