The most interesting thing is discovery this cave by a little boat row that is slowly rowing to amazing lagoon, come here visitors are not only admire a beauty natural that is also can see the salty water flora

The tunnel cave lengthen is about 500 m, it go throught the middle arange of impossing limestone mountain, the largest internal of it is 50 m wide , from the ceiling and along two grotto side are multiple stalactile shape as wanting to show the forming genious of god, visting this tunnle grottor is like getting lose in fairy world.

Along the sea shore is salty water jungle consist a few hundred years tree, here are also a huge sea foods source within not really big region. In 2007 the tunnle cave Cai De been mention on promoting plan of Bai Tu Long and Van Don Island, this will be highly recommended attraction for discovery Bai Tu Long  holiday schedule.