The United Nations is like a big club of countries (like a school club) where they work together to solve big problems. One very important problem they want to solve is making sure people don't forget about the Holocaust, which was a very bad time in history. The Holocaust happened when people in Germany decided they didn't like Jewish people and wanted to hurt them. They made them do hard work and put them in concentration camps, where many of them died.
The United Nations created a special place called a memorial to remember the people who were hurt and died during the Holocaust. A memorial is like a big park with statues and things to look at, but instead of just being pretty, it's a special place to remember what happened. When people go to the United Nations Holocaust Memorial, they can learn about the bad things that happened during the Holocaust and how important it is to make sure that something like that never happens again.
The people who work at the United Nations Holocaust Memorial want to make sure that everyone knows how bad it was and why it's important to be kind to all people, no matter what they look like or where they come from. They hope that by remembering the Holocaust, we can learn from mistakes and make the world a better and safer place for everyone.