The Source de la Loue is one of the Jura's most beautiful natural sites. It is spectacular to see water spring from a vast grotto located at the foot of a 100 m-high cliff. Various experiments have shown that river Doubs water comes into contact with the spring water. In 1901, after a fire in a Pontarlier factory, a million litres of absinth flowed into the Doubs. Several hours later, the presence of this alcohol could be found in the spring !