A dance begins beneath the outstretched branches of the giant umunyinya tree in Rwanda. First there is drumming and clapping, then the lead dancers step into the center of the gathering. The dancing subsides and the gacaca court, the community hearin...

Auschwitz. Hiroshima. Cambodia's killing fields. The World Trade Center. The mass graves of Rwanda. These places of violent death have become part of the recreational landscape of tourism, an industry that is otherwise dedicated to pleasure and escap...