Is there a way to map a collection and a property which points to an element of that collection (i.e. to have something like "addresses" and "mainAddress" in the same entity)?

Just use a normal Java property which accesses your mapped collection and don't map it at all.

Uhm. But how to reflect the fact that there is a field in the table which points to the id of the dependent object, which is also included in the collection? It should be mapped, shouldn't it?

Map it as an additional private property, I'd suggest.

Or simply map it as a one-to-one, now that I think of it ...

Yes, but wouldn't this create problems with duplicate insertions when persisting the containing entity?

Hibernate resolves something like this, as long as you set up your java object relationships correctly.