"Russian scientists have breached an ice sheet that has sealed subglacial Lake Vostok in Antarctica for more than 20 million years..."

"... at a depth of nearly 4,000 meters, reaching a critical stage in a decades-long drilling project... Lake Vostok is the largest of a network of hidden subglacial Antarctic lakes... It is also one of the largest lakes in the world."

Reports The Moscow Times, which adds this spicy tidbit:

Rumors that these lakes were also home to secret German submarine bases during World War II are also being revisited in the wake of renewed excitement, driven by Nazi claims that they had created an "unassailable" Antarctic fortress and by archival evidence describing the construction of ice caves.

No Nazis in the NYT report, which pays attention to the threat of pollution from the kerosene and Freon used in the drilling and the prediction — which was supposedly correct — that the borehole would freeze up, sealing in the chemicals, as soon as the drill reached the lake.