The Caves of Han-sur-Lesse is one of the most popular tourist destinations in Belgium. The caves are located on the Lesse River which - at the locality where the cave had been formed - disappears in the underground, under the hill of Boeme, also called Boine. The Caves of Han-sur-Lesse are the result of the underground erosion of the limestone hill. They are approximately 1 km long (in a beeline) . The temperature in the caves of Han – sur – Lesse is constant (13°C) and the humidity inside the cave space is very high.
The tour around the Caves of Han-sur-Lesse lasts between 1 and 1.5 hour. A parto of the tour is a sound and light show that takes place in Salle du Dome, the largest cave in Belgium. This chamber is 62 metres high. Another attraction in the Caves of Han-sur-Lesse is a seven-metre-tall stalactite, allegedly some 120 thousand years old. The tour around the Caves of Han-sur-Lesse is ended with a short boat ride and a cannon shot to demonstrate the cave´s acoustic properties.