Auschwitz, January 1945
Although the Germans attempted to destroy the camp, there was still plenty of evidence left for the Soviets to find. Just to name a few, they found over 800,000 woman's outfits, more than 100,000 men's suits and about 14,000 pounds of human hair in standing warehouses.
Stutthof, May 9, 1945
Since the evacuation by the German's was so harse, only a mere 100 prisoners were left to be liberated by the Soviet forces.
Sachsenhausen, April 22, 1945
On April 21st, 1945, SS camp guards began forced evacuation of some 33,000 prisoners on foot. On April 22nd, 1945, Soviet forces liberated the camp and found only about 3,000 ill and weak prisoners left behind in the camp. An estimated 200,000 were believed to have been held in Sachsenhausen.
Ravensbrueck
Evacuation of Ravensbruck began in March 1945 when many prisoners, both men and women, were sent to other camps such as Sachsenhausen, Mauthausen and Bergen-Belsen. Soviets liberated the camp between April 29-30th, 1945 and found over 2,000 sick men, women and children.
Main Source:
http://www.ushmm.org/
http://www.ushmm.org/