When visiting Poland to visit the site of camps, ghettos, graves, where all and how often should the blessing over seeing Jewish graves be recited?
When a person sees Jewish graves he makes the special bracha, but this is only if he hasn’t seen Jewish graves in 30 days. Therefore if you didn’t see any Jewish graves in 30 days you would say the bracha on the first graves that you see and that is it. Although it is very sad to see the ghettos and camps, however there isn’t any specific bracha that we say when seeing them.
OC:H 224-12,13, M:B ibid 17.