The most famous in the world of "blue hole"
"Blue hole" - a submarine cavity that appeared thousands of years ago.
Another striking feature is that they contain fresh water from underground streams, which is mixed at the sea surface with salt water.
Great Blue Hole, Belize
"Great Blue Hole" is located near the coast of Belize, a small country on the east coast of Central America, in the Caribbean.
This round giant sea basin, formed by the melting of ice about 15,000 years ago, when sea level was very low.
Its diameter is 300 meters, depth - 120, and it is on the list of World Heritage sites. This hole is one of the five most popular destinations for divers.
It has a lot of fish, and it is one of the most amazing places on earth.
Dean's Blue Hole, Bahamas
The Hole "Blue Death" - one of the largest in the world. It has a diameter of about 115 m in the sea and is located above the cave 100 meters in diameter. Its depth of about 200 meters.
It is close to Clarence on the coast of Long Island in the Bahamas. It has a rich underwater life and is suitable for scuba diving and snorkeling. "Dean's Blue Hole" is different in many ways, since it is connected to the Atlantic Ocean through the entrance on one side, and on the other - between the cliffs and white sand beaches.
Hole Blue Dragon, China
has a depth of 300 meters, as well as the bright blue color when viewed from above.
It is almost 110 meters deeper than the Dean's Blue Hole.
Guam to Blue Hole, Big Reef
The Blue Hole is located approximately 30 meters from the western coast of Guam, an island in the western Pacific Ocean.
This rare blue hole is an open bay, which starts from a depth of 18 meters and up to 40 in the sea.
Since the beach with a blue hole - a rock about 45 meters high and the entrance to the beach is not all, access is only possible by boat.
Blue Hole "Doors", Malta
This is another popular among divers place on the island of Gozo, the Maltese archipelago, the Mediterranean Sea.
This area opens onto a beautiful arch Azure Window and begins with a fantastic 10-meter indoor swimming pool sea, which leads to a large cavity in the open sea.
Dahab Red Sea, Egypt
It is located in the south-east of the Sinai, the Red Sea coast. An underwater depression 110 meters deep.
Around the blue hole is a large amount of corals and a large variety of fish. However, it is considered a death trap as killed between 150 and 200 divers!
Watling Blue Hole, San Salvador
Trench, located in the east of the Bahamas, is connected with the ocean underground tunnel.
Santa Rosa Blue Hole, New Mexico
This bell-shaped pool for diving and training. This is one of the most popular dive sites, which was once used as a fish farm.
Crystal clear water has a constant temperature of 17 degrees Celsius. However, the surface of Santa Rosa has a diameter of 24 meters and a depth of 40 meters.