It's not the same feeling visiting Sachsenhausen Memorial, located in the northern community of Oranienburg. The people here were relatives and neighbours of people still around right now. (The town of Oranienburg is literally a 5 minute walk away, and was here during World War II). The Nazis built this central camp just north of the capital city, and today it is a huge museum dedicated to those who were imprisoned, tortured, and executed here.
I travelled on the train S1 to Oranienburg) and from central Berlin it is a quiet, 30-minute train ride. If you are interested in avoiding crowds, go on a Saturday and go early in the morning (8:30 am). There was virtually no one there until around 11:00 am--people sleeping in on the weekend means more solitude to soak in the atmosphere.
After World War II, the camp was used by the Soviets until 1950, and so mass killings and forced labour continued.
From a "hands on" perspective, it was fascinating to walk the grounds, touch the walls, sit in the barracks and visit the crematorium (and the ruins of the gas chambers). A regular museum can be interesting, but it is visceral to enter the infirmary, walk down into the cellar, feel the day turn from warm to cool, and to smell the dank, rusty rooms.
There are multiple buildings here (like more modern museums built specifically to house artifacts and show movie footage. There are many different rooms and buildings that showcase personal artifacts and documents. Not every historical building is available to wander through, but many are open or are in the process of being restored. Wandering around and exploring is encouraged--there are lots of multiple ways to get somewhere, and often a quick diversion leads to a whole different discovery. Despite this being one of the Nazi's smaller concentration camps, it is still massive-- walking it takes at least three hours, and there are lots of places (like benches) to just sit, take a moment and think. I highly recommend this half-day trip from Berlin if you are looking to see, hear, smell and feel a piece of modern history.
Tip: bring some rain gear and/or sunblock-- it went from sunny to torrential downpour to scorching hot and sunny all within 45 minutes.