Sachsenhausen concentration camp is just a short train ride from Berlin, and then a mile walk from the train station. We took a guided tour which was really with it. Our guide took us all over the camp and told us all of the crazy and interesting things that had happened there.
It is a really eerie feeling being at a place like this. A lot of evil happened here. That is why it is important to go there and remember what happened, and never let something like this ever happen again. Inside tip: Don't take selfies here, it is considered rude.