How lovely is your dwelling place,
O LORD Almighty!
The NIV Study Bible says that the author of this psalm was probably a levite (whose normal function was temple service) who had been barred from access to the temple. The notes say that it may have been when Judah was being attacked.
The dwelling place of God is a place that is longed for. It is lovely, in the sense of something that is loved. This author, though wanting to be back in the temple, is expressing his love for the nearness of God.
There is no better place to be, than where God dwells.