Don't mix up " sore” and "are". in these case following.
The speaker went to a restaurant that the hearer don't know and he is talingk about that restaurant....
「きのう レストランへ行ったんだ。そのレストランは やすくて すごくおいしかったよ。」
The speaker and the hearer went to a restaurant yesterday. They are talking
about that restaurant....
「きのうの レストラン よかったね。こんど あの レストランに かのじょと いきたいな。」
Regardless of doncreat things or abstract things, "ano" is the
mutual information between the speaker and the hearer. The things expressed
with "sono" are the things that only the speaker knows.