Ploučnice Gap - Devil's Hole, Hell's Esophagus or Thunderstorm

A small river named Ploučnice originates below Ještěd and also flows through the town of Stráž pod Ralskem to the town of Mimoň. Four kilometers from the first-named town, there is one very interesting place.
After several meanders, a straight section follows, at the end of which the first rocks appear, and after a while one sees the beginning of a gap. This is one of the possible starting points for the river, but above all here…