Recognising the area's contribution to the quality of life in the city, Parisians often refer to the immense park as 'the lungs of Paris'. In total, Bois de Boulogne holds 95 kilometres of roads and walking paths, three rivers, two lakes, and a racecourse running the length of the old fortifications of the capital. The result is one of the greatest locations for outdoor activities in Paris, offering plenty of picturesque places to walk, bike and jog.

Bois de Boulogne is the only remaining part of an immense ancient oak forest known in the early Middle Ages as Rouvray. In the 7th Century, Childeric II donated the area to the powerful Abbey of Saint-Denis, which went on to found several monasteries. Nearly 500 years later, Philip Augustus convinced the monks to sell him back the main area of the woods, as he wished to establish a royal hunting reserve there.

During the time of the Hundred Years War, the forest became infamous as a dominion of robbers. In the early 15th Century, the army of the Duke of Burgundy burned a large part of the Rouvroy. Soon afterwards, King Louis XI commissioned the reforestation of the part of the estate that is nowadays the Bois de Boulogne. In 1526, King François I built the Château de Madrid, thus making the area a major venue for celebrations. In the early 17th Century, Henry IV planted more than 15,000 mulberry trees, hoping to stimulate the emergence of a local silk industry.

The Bois de Boulogne became a public park in 1852, under the rule of Napoleon III. During the next decade, it was carefully landscaped into a recreation spot for the upper classes by Baron Haussman. Inspired by the layout of Hyde Park in London, he included in the project a maze of paths winding through the woodland as well as a number of large, open lawns.

Such is the shape of the Bois de Boulogne today. The woods feature an impressive collection of tree species, such as hornbeam, beech, linden, cedar, chestnut and elm, as well as several exotic species, including redwoods. Most of the 35 kilometres of footpaths, 8 kilometres of cycle paths and nearly 30 kilometres of riding tracks are serpentine roads. The two wonderful lakes are located at different levels and are connected by a waterfall. The earth that was excavated to create the lakes was later used to create the impressive Butte Mortemart.

The northern section of the park holds Jardin d'Acclimatation, a theme park inaugurated in 1860. It includes a mini-zoo and a variety of other attractions for both children and adults. The entertaining Bois de Boulogne is also home to several tennis courts, football and rugby fields, bowling centres, boating ponds as well as other group sports facilities. The Bois de Boulogne's famous Hippodrome de Longchamps is popular among fans of horseback riding. Erected in the 1850s, it's still the largest of its kind in Paris.