Lake Baikal ( Russia )
is the world's oldest and deepest lake.
it is the second most voluminous lake, after the Caspian Sea. As the most voluminous freshwater lake in the world, with an average depth of 744.4 m ( 2,442 ft ).
Lake Baikal contains roughly 20% of the world's surface fresh water.
The Congo River ( Africa )
(also known as the Zaire River) is the deepest river in the world, with measured depths in excess of 230 m ( 750 ft ).
It is the second largest river in the world by volume of water discharged, though it has only one - fifth the volume of the world's largest river, the Amazon.
Nemo 33 ( Brussels, Belgium )
that is home to the world's deepest swimming pool. The pool itself consists of a submergedstructure with flat platforms at various depth levels.
The pool has two large flat-bottomed areas at depth levels of 5m ( 16 ft ) and 10m ( 32 ft ), and a large circular pit descending to a depth of 33m ( 108 ft ).
The Mariana Trench ( Pacific Ocean )
is the deepest part of the world's oceans, and the lowest elevation of the surface of the Earth's crust. It is currently estimated to be up to 10,971 m ( 35,994 ft ) deep. It is located in the western Pacific Ocean.
The Great Blue Hole ( Belize )
about 60 miles away from Belize City. It is believed that this hole is the world’s largest sea-hole. It is about 125 meters deep( 407 ft ) and its diameter is about 300 meters wide ( 984 ft )
Kola Superdeep Borehole
Is the result of a scientific drilling project of the former USSR. The project attempted to drill as deep as possible into the Earth's crust. Drilling began on 24 May 1970
It reached 12,262 metres ( 40,230 ft ) in 1989, and is the deepest hole ever drilled, and the deepest artificial point on the earth
Cenote Poza El Zacaton
A sinkhole is a nature-made hole on the earth surface caused by removal of soil or bedrock, usually both, by water.
It is the deepest known water - filled sinkhole in the world with a total depth of 339 metres ( 1,112 ft ).
The Cave of Swallows ( Mexico )
( Spanish: Sotano de las Golondrinas ), is an open air pit cave in San Luis Potosí, Mexico.
The elliptical mouth, on a slope of karst, is 160 by 205 feet ( 49 by 62 m ) wide
The floor of the cave is a 1,094-foot ( 333 m ) freefall drop from the lowest side of the opening, with a 1,220-foot ( 370 m ) drop from the highest side