Drainage in Moldova is to the south, toward the Black Sea lowlands, and eventually into the Black Sea, but only eight rivers and creeks extend more than 100 kilometers. Moldova's main river, the Dniester, is navigable throughout almost the entire country, and in warmer winters it does not freeze over. The Prut river is a tributary of the Danube, which it joins at the far southwestern tip of the country. Over 95% of the water circulation in Moldova flows into one of the two rivers - the Prut or Dniester. Of Moldova's well-developed network of about 3,000 creeks and streams, all draining south to the Black Sea, only 246 exceed in length, and only 8 exceed .