The ancient spiritual tradition of the Church, explicitly connects the enclosed-contemplative life to the prayer of Jesus "on the mountain", or solitary place not accessible to all but only to those whom he calls to be with Him, apart from the others.
The enclosure therefore, even in its physical form, is a special way of being with the Lord, of sharing in Christ's emptying of Himself by means of a radical poverty, expressed in renunciation not only of things but also of space, of contacts, of so many benefits of creation.