A sound and light show is seen at the Cave of Han in Han-sur-Lesse, Wallonia, Belgium, on Sept. 4, 2021. As an important tourist destination famous for its geological scenery in Wallonia, the Cave of Han has been visited by over 23 million tourists. (Photo: Xinhua)
The geological scenery is seen at the Cave of Han in Han-sur-Lesse, Wallonia, Belgium, on Sept. 4, 2021. As an important tourist destination famous for its geological scenery in Wallonia, the Cave of Han has been visited by over 23 million tourists. (Photo: Xinhua)
A sound and light show is seen at the Cave of Han in Han-sur-Lesse, Wallonia, Belgium, on Sept. 4, 2021. As an important tourist destination famous for its geological scenery in Wallonia, the Cave of Han has been visited by over 23 million tourists. (Photo: Xinhua)
The geological scenery is seen at the Cave of Han in Han-sur-Lesse, Wallonia, Belgium, on Sept. 4, 2021. As an important tourist destination famous for its geological scenery in Wallonia, the Cave of Han has been visited by over 23 million tourists. (Photo: Xinhua)