There are not very many places on each where you walk under a glacier. This is one of many which are sliding to their demise, slowly grinding it's way to the ocean. The ground inside is being pulverized and turned info fine grains sand from the massive weight of the ice.
Some of these glaciers are moving several feet per day and melting at rates never seen in recorded history. While beautiful to look at the photograph, their disappearance is rapidly approaching and the geographical changes are just beginning at an exponential rate.