Angela Merkel has laid a wreath at the former Nazi concentration camp of Dachau, in the first such visit to the site by a German chancellor.
She made a short speech saying the camp "fills me with deep sadness and shame" and said it was a warning of the dangers of indifference.
She said the camp stood for "a horrible and unprecedented chapter of our history".
Mrs Merkel also said the "vast majority of Germans" had closed their eyes to what was going on.
Afterwards, she laid a wreath of flowers and toured the remnants of the camp late on Tuesday afternoon.
The BBC reports the visit was part of Mrs Merkel's election campaign and was followed by a rally in a beer tent nearby. Political opponents called the combination "tasteless".
Some 30,000 people died in Dachau before it was liberated by US soldiers on 29 April 1945. It was the first camp to be built by the Nazis in March 1933.