I visited Dachau concentration camp in germany in march, it's a very somber day, it was cold and fairly rainy, i doubt it ever looks sunny in such a place but it was something I needed to do to fully grasp the reality of it.  To walk into the barracks was the most thought provoking part as you could visualize the duhumanization of the people who were held there as they were originally treated like people and then eventually as animals.