The Dry Valleys unusual due to the positioning of the Transantarctic Mountain Range which force air flowing over them upwards so they lose their moisture so snow and rain doesn't fall. The mountains also prevent the flow of ice down the valleys and strong winds of up to 200 miles per hour blow down from the interior causing whatever ice that makes it into the valleys to evaporate.
They are one of the most extreme desert climates anywhere on earth, a cold desert where the mean annual temperature is between 6 degrees F. to -22 degrees F. depending on the exact location.
There are three large valleys, Taylor Valley, Wright Valley and Victoria Valley. Taylor Valley was first discovered in 1901-1904 and surveyed in 1910-1913. The valley is hemmed in by tall mountain peaks and no further exploration of the surroundings was made until the 1950's further further valleys and the extent of them was discovered from aerial photographs.
There is a lake in Taylor Valley. There is a myth says that when the party from Scott's 1910-1913 expedition camped nearby, they took what they assumed was pure drinking water from this lake to be afflicted by a bad case of diarrhea which resulted in the usage of large amounts of toilet paper. The brand name of this paper was "Chad" and so the name was given to the lake. Actually, the diarrhea caused by the lake water was likely due to decaying seals in the lake.
Blood Falls was first discovered 1911. Its reddish-brown color is due to iron oxides coming from a sub-glacial lake under the Taylor Glacier. The unusual chemical properties of the lake water allows bacteria to survive.
The large very salty lake beneath the Taylor Glacier occasionally overflows causing Blood Falls to flow. It is the only place on earth where a deep very salty lake which harbors microbial life. This simple bacterial ecosystem do not need to derive energy from the sun and may indicate similar ecosystems elsewhere in the solar system such as on Mars.
Another of the Dry Valleys oddities is that they have mummified seals which have been found up to 40 miles from the sea and at altitudes of up to 5000 feet. These corpses have been carbon dated and found to be up to 2600 years old even though they appear to have died recently. The cold dry winds desiccate the carcass and there are no animals to eat the carcasses. No one is sure how or why these seals end up there and most of them are less than a year old, but it is thought that they just got lost. It's also believed that they were injured on the rocks and because their stomachs were almost empty, that they starved to death. In addition to the seals, a few penguin carcasses have been found.
The Dry Valleys have the Onyx River which is the longest river in Antarctica, though strictly speaking it isn't a river but a seasonal melt water stream and only flows 6-8 weeks a year. It flows away from the sea, its water never reaching the ocean. It's less than two feet deep and the width of several feet varies.
The river ends up in Lake Vanda which is saltier than any other natural body of water on earth. It was discovered in 1961 and does not freeze despite temperatures of down to 22 below because it is so salty.
One of the largest and clearest rock features is a region known as the labyrinth consists of a series of channels carved into a layer of bedrock over 300 feet thick.
The Dry Valleys also have a series of more than 20 permanent lakes and ponds. A number of these are extremely saline or in the case of the larger and deeper ones are strongly layered by depth becoming more saline the deeper you go, the most extreme of them all is Don Juan Pond described above which is the only one that doesn't freeze at the surface. Some of the smaller lakes freeze right down to the bottom in the winter. In recent years a series of underground interconnected lakes have also been found.
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