The first place that you see when coming into Terezin is a massive cemetery and a brick fort that just looks plain creepy. After a couple of hours of wandering around inside, we also discovered that the creepy feeling that the "small fort" as it's known gets worse rather than better. It's one of those places that you can't really describe without sounding corny as walking through dismal barracks, execution grounds and past a swimming pool made by forced labourers who were later killed in some way is a profoundly moving experience.
After a day trip to Terezin, it was a real relief to return to Prague. It's worth seeing something a little emotionally challenging every now and then though, and I totally recommend it for anyone who is interested in history and wants a little more from a weekend in Prague than beer and pretty buildings.