how long does the tour take?

You dont have to do the tour. There is a fully guided tour option available. But we just strolled around at our own pace....took about 1 hour 30 mins to 2 hours to get around it.

Exactly. We did not do the tour. We were there for 1 hour and a half. When you are inside you can read signs and watch some videos. It is a sad place.

It's so impressive that I would recommend you put aside a whole day for it!

2h more or less