Answer:
Step-by-step explanation:
Blest is a special term. It means that God put a special effort into such a place. If you prefer, it means that the place is very beautiful.
It is a spiritual term that signifies that there is something in the place that cannot be found anywhere else. The poet means to convey how moved he was to know about such a place. It is a part of the world that is somehow set apart from everywhere else and those who live there are blessed because they get to live there.
The poet is lucky indeed that he has eyes that can see such beauty.