Forest of Fontainebleau, Protected national forest in Seine-et-Marne, France

The forest of Fontainebleau is a wooded massif in Seine-et-Marne and Essonne, France, covering about 25,000 hectares, of which 21,600 hectares are public state forest. Its canopy mixes deciduous trees and darker conifers over gently undulating ground, with pale sandstone outcrops breaking the tree cover. The state forest alone covers 17,072 hectares and ranges from 42 to 144 metres in altitude.

Philippe I acquired the county of Gâtinais in 1067, giving the crown control of the whole forest; a royal residence existed by 1137. François I rebuilt the castle from 1527 and created the office of Grand Forestier. In 1853, 624 hectares were withdrawn from logging as artistic reserves, and the imperial decree of 13 April 1861 raised this to 1,094 hectares, making Fontainebleau the first nature reserve in the world.

Claude-François Denecourt earned the nickname Sylvain while working in these woods, and his system of colour-coded trail markers still guides walkers today. French climbers have used the sandstone boulders scattered among the trees for generations to train before heading to the Alps, naming hundreds of individual rocks over the years.

The woodland sits roughly 60 km (37 miles) southeast of Paris and can be reached through multiple entry points, each leading to different sections and terrain types. Main routes remain passable year-round, though some paths through rocks and undergrowth can become slippery during wet conditions.

The Denecourt plaques from the 19th century still stand at different points through the woodland, bearing poems and texts meant to help walkers navigate and contemplate nature. Many boulders carry engraved names or symbols placed by climbers over decades to mark their preferred routes.