This term has other meanings, see Blue hole (values).
Blue hole (from the English. Blue Hole is an underwater vertical cave near Dahab in Egypt.
It is surrounded by coral reefs karst sinkhole depth of about 130 meters. From a depth of 52-55 meters, the cave is connected to the sea by a passage. Overhanging over the passage corals formed a kind of arch, hence the name of the Arch.
The traditional route for Amateur divers consists of diving through the Bells (200 m North of the Blue hole), moving along the reef wall and entering the Blue hole through the upper isthmus called the Saddle of the Arch (at a depth of 6-7 meters). Continue reading
The Zhangye Danxia rocks in southeastern China are a unique geological phenomenon. Lush rolling hills are reminiscent of the paintings created by nature itself.
The colored rocks Of Zhangye Danxia (Zhangye Danxia Landform) are colorful rock formations of a geological Park in Gansu province. Colored rocks consist of red sandstones and conglomerates mostly of the Cretaceous period.
The study shows that approximately 100 million years ago, this place was a huge internal pool. The water carried silt from the surrounding area. Continue reading