Last week, survivors of Buchenwald concentration camp gathered at its former site to celebrate the anniversary of its liberation on April 11, 1945. Over the 8 years it was in operation, the camp held about 250,000 people, nearly a quarter of whom died.

Photographer Lisi Niesner was able to take a few poignant pictures of some of this year’s visitors…

Petro Mischtschuk, 87, Ukrainian

Victor Karpus, 88, Ukrainian

Eva Pusztai, 88, Hungarian

Jakob Silberstein, 89, Polish

Elling Kvamme, 94, Norwegian

Vasile Nussbaum, 83, Romanian

(via NBC)