In the Daily Office, one frequenty recites a Venite which proclaims, "In His hand are the caverns of the earth; the heights of the mountains are His also." This is probably based upon Ps 95:4.
We are accustomed to looking up to the heights in our contemplation of God, and many feel somehow closer to God when on a mountaintop. But I am also moved by contemplation of the truth that not only the obvious mountains but the inapparent caverns are in His hand, are his workmanship.
As a child I visited various caverns with my parents, the largest being Luray Caverns in Virginia. The stories of the discovery of these caverns have a certain similarity. For millenia, their existence is hidden beneath the earth, and one day someone finds a sinkhole, or cool air emanating from under a rock, and digs a little to discover breathtaking beauty that has lain unknown and unappreciated beneath our feet for hundreds of years, thousands of years. All that time, slow millimeter by millimeter and unappreciated by mortal eyes, God has carved chambers filled with beauty and mirror pools and deep quiet. A work of removal and accretion, the work of Water moving through and out of Rock.
We are an impatient race. What work is God doing beneath our feet, unknown to us, over the decades of our own lives and over the centuries of the life of the City of Zion? What caverns of beauty will be revealed to us in that Day when we shall see clearly and know as we are known? What shapes are being carved out of our stony hearts by the slow but relentless movement through them of the water of life?