More than 70 subglacial lakes have now been identified by both airborne radioecho sounding (RES) and satellite altimetry underneath the East Antarctic Ice Sheet. See Figure 1. The largest of these is Lake Vostok, located in the interior of the plateau of East Antarctica. It lies under 4 km of ice with an average depth of more than 500m. It measures 240 km long, 50 km wide and is 14,000 km2 in area, its water volume is estimated to be 2000 km3. These dimensions put it as one of the ten largest lakes in the world. It is theorized that the lake water is maintained in a liquid state by geothermal heating, pressure and insulation by the overlying ice. The presence of a layer of sediments on the lake bottom plus the findings of microbial forms in ice cores taken from above the lake suggest that life forms may yet be found that have been isolated from any outside interference for at least 1 million years.