A map has been made of all of the (former) synagogues in Europe
>If you've ever wondered how many synagogues there are in Europe, now you have an answer: 3,318
>Less than a quarter are in use as a synagogue. Others are disused, or converted to a number of other purposes—examples include a swimming pool, a bar, police station, a funeral parlor, and a mosque.
>The point of mapping all of Europe's remaining synagogues—before World War II, there were about 17,000—is to identify those in imminent danger of ruin. The foundation has identified around 160 houses of worship which are in imminent danger of ruin.
http://archive.is/F3bs1
You can interact with the synagogue map here
http://archive.is/n5KRm