Forêt de Fontainebleau

The boulders erupt out of the forest floor in sandstone clusters — some the size of houses, nearly all of them climbable — scattered through tens of thousands of hectares of oak, beech and pine that begin an hour south of Paris. Fontainebleau is France's bouldering playground, a painters' forest and a royal hunting ground layered on top of one another under the same canopy.

The forest of Fontainebleau is the green lung of the Île-de-France, a massif of superlatives and exceptions in the words of the foresters who manage it, and its sandstone — the rounded, gritty boulders left standing in the sand — made it the birthplace of bouldering: thousands of climbing problems, no ropes, marked out in colour-coded circuits from children's to expert, so that a family and a hardened climber work the same rocks. The Barbizon painters got here first — Corot, Millet and Rousseau painted these trees and rocks in the open air in the 1830s, and Millet's studio in Barbizon is a museum. Trails run from flat strolls to full-day walks, and the château at the forest's edge, a royal residence for centuries and a World Heritage site, is the second reason to come. The forest office closes sectors after fire or storm; check before you set out.