When the Holocaust ended more than 60 years ago, the world said "Never again." Yet crimes against humanity continue. As an activist and author of Night, Elie Wiesel has fought against some of humanity's most horrific acts in Bosnia, Rwanda and Darfur.

Voices on Genocide Prevention
How can you lend your voice to help stop genocide around the world? Education is the first step. Visit the United States Holocaust Memorial Museum's website and listen to Voices on Genocide Prevention podcasts.

More from The Oprah Winfrey Show
Darfur
In Sudan's Darfur region, human history repeats itself. The Janjaweed militia, an Arabic group supported by the Sudanese government, is systematically murdering the region's black tribes.

• George Clooney reports from Sudan.

Rwanda
In 1994, the world stood by again as another genocide exploded in Africa. For 100 blood-soaked days, Rwanda's Hutu majority systematically slaughtered 800,000 minority Tutsis.

• Oprah talks with the real-life hero of Hotel Rwanda, Paul Rusesabagina.
• A Tutsi survivor shares her story.
• CNN's Anderson Cooper on covering the massacre

Uganda
Since the late 1980s, the government of Uganda has been engaged in a brutal civil fighting against a rebel group called the Lord's Resistance Army—or LRA—that abducts children and tortures them into soldiers.

• Lisa Ling and a woman who survived
• "Nightwalkers:" the children trying to escape the LRA

The Democratic Republic of the Congo
Since the mid-1990s, the Congo has been a war-torn nation. The country's most recent conflict stems from a struggle for resources and power. Four million people have already been massacred, and every day, rape is used as a vicious weapon against women.

• Lisa Ling travels to the Democratic Republic of the Congo.
• Read letters Congolese women sent to O, The Oprah Magazine.