Tourists visit the Grotto of Han-sur-Lesse in Belgium.
The Grotto of Han-sur-Lesse in Belgium is featured in this story.
L/S of men walking along a river bank holding flares. Inside the caverns the flares light up the caves. Various shots of the men walking through the caves "Like an army of super glow-worms on the march."
The tourists then take a trip on the underground river. Small boats are propelled through the caverns, smoke from the flares fills the caves.
Was an item in Pathe Pictorial issue number 678.
Note: flash-frame intertitles.