I went to Auschwitz 15 odd years ago when travelling through Poland and other parts of Eastern Europe. I was interested in history at school, but am no expert on WW2 and it was interesting to experience the direct impacts that the war and occupation had on various places in the region. With the exception of the Channel Islands, the impact on Britain was more remote and a different kind of danger. Bombing raids were of course lethal and destructive, but that's not the same fear as people in the streets who may hunt you down.
There were Jewish roots in my family. I'm not sure if they were sufficiently diluted that the WW2 generations would have escaped the attentions of the Nazis in the event of an invasion. I remember it hitting me that the list of other groups targeted in the Holocaust, homosexuals, the disabled and Jehovah's Witnesses would have directly impacted many of my contemporary family members.
I'm not generally drawn to gory. I went to Auschwitz because the history is so important, uncomfortably so. There is a difference in intellectually knowing from a school textbook or documentary and physically standing infront of the evidence that 6 million is not just a big number, it was individual human beings who were stripped down as commodities before being enslaved to work to death or slaughtered en-masse. Seeing their hair that was shaved off to make sacks, or the removed prosthetics, glasses, shoes hit it down to the level of individual human beings (which is why Anne Frank's story is so poigniant).
The basic crude sheds that people were piled into also hit hard, imagining the overcrowding that people were expected to exist in. I remember the feeling of bleak, quiet. I honestly believe that the scale of suffering has permanently marred that place.
It is so, so important that places such as Auschwitz are preserved as they were. To keep that history tangible. To be a memorial to the people who were murdered there and elsewhere. I don't think it should be compulsory, but it should be there for people who have the opportunity to go.