My grandfather left Germany because of the holocaust in the late 30's. I am travelling to Mannheim in a couple days. I have his old street address, but it's for a street that doesn't exist anymore in google maps. They house was rather large and they were a prominent Jewish family in the city. I was thinking of visiting a synagogue to see if they had more info. Are there any online resources or any resources in the city for people that are trying re-trace their family's history?