A seemingly peaceful fountain awakens, begins to bubble. Suddenly a fountain of 9°C cold water shoots into the sky, bubbling upwards for six minutes. Then, just as in a flash, the spook is over, the "Brubbel" as the locals affectionately call their phenomenon, calms down.

The basis for this natural spectacle is a carbonated spring, like hundreds of others in the Eifel. At the beginning of the 1930s, the people of Wallenborn wanted to use it for industrial purposes and began drilling. But during this attempt, chunks of earth and water flew around their ears. They had stumbled upon a chamber in which rising CO2 collected and escaped to the surface with force and water.

The fact that the "Brubbel" still spews out at such regular intervals today can be explained with the help of a comparison: similar to a bubble bottle that is shaken, the pressure in the underground chamber rises. At some point - after 35 minutes to be precise - this pressure exceeds the pressure of the water column above. The Wallende Born is born - the cold-water geyser in the Eifel.

The 3.5 km long Brubbel Trail follows the Wallenden Born. The information points along the Brubbel Trail provide insights into the village life of Wallenborn, the dialect of the village and the special features of the landscape.The Volcanic Eifel Trail "Hinterbüsch Trail" also takes you through Wallenborn on your hike through the Eifel.