In most cases. In the places where they stood are dense blocks of apartments. What he is saying, is that is it not possible to return to something that doesn't exist. Even where the actual homes do exist, the neighborhoods and--indeed the whole country have changed so much--that the dream that people who wish to return are holding onto does not exist.
In Cameroon, suicide bombing toll rises to 19 dead, 143 wounded (Reuters)
from the article: Dividing the Land of Israel into two states is a moral imperative