A Nazi concentration camp is something that everyone should visit at least once in their lifetime. Terezin is probably easier to visit than most. It was a holding camp rather than an extermination camp. It was the only camp for Jews that the Red Cross was allowed to visit, although those visits consisted mostly of elaborately-prepared banquets. The Red Cross was never allowed any private interviews with detainees.
The hardest part of the visit were some of the pictures drawn by children at Terezin.
Children were a crucial part of the Nazi scheme to exterminate Jews. If they were allowed to live, they would eventually turn into mature adults and add to the Jewish population. Grandparents were somewhat safer. They could be used in work details, would probably die because of the horrible conditions so no need for gas chambers, and no worry about producing more Jews.
On our bus transfer the next day to Vienna, we stopped in Bratislava for lunch and a city tour.