Le Hérou, Rock formation in Ardenne, Belgium.

Le Hérou is a rock formation in the Belgian Ardennes with steep cliffs and natural stone structures rising from the forested landscape. The rocks display layered formations and varied surfaces shaped by weathering and geological processes.

Le Hérou was listed as exceptional Walloon heritage on 15 October 1937, with separate classifications for the Houffalize and La Roche-en-Ardenne communes. It joined the list of exceptional heritage of Wallonia in 2009 and is also a Natura 2000 site. Around 1913 Brussels professor Chargeois described a first walking path around the site, and in 1923-1924 he laid out a network of local trails for the Touring Club; hotels and the Belvédère lookout tower followed, and since the 1920s the rock has been a highlight of the Ourthe valley.

From the 1920s Le Hérou was promoted as a highlight of the Ourthe valley: Brussels professor Chargeois laid out a walking route around the site and, for the Touring Club, a network of local paths in 1923 and 1924. Maurice Cosyn, who traced the first long-distance Ourthe trail, later published a guide to Nadrin and Le Hérou with 16 routes of 3 to 16 km. Hoteliers of the time helped create and maintain the paths, and the Belvédère tower let visitors see the river's six bends.

Multiple marked hiking paths lead to the formation with parking areas and information boards at main access points. The trails are accessible to visitors of different abilities, though some sections are steep and rocky.

The belvedere near the end of the rock spur, about a hundred metres from its tip, was known as the "belvedere of the six Ourthes": from it the river could be seen appearing and disappearing six times. It has been closed to the public since 2009, and the Hotel Belvedere it belonged to stood derelict by 2018.