The vertical shot, no:3, shows off the actual chemistry and physical formation best while the wide shots give away the enormous scale of the rock formation. This formation must have taken milions of years till it gained this aligned/stacked-stilts look. Must have a special mineral make up that crystallizes in this manner.
No wonder they are likened to a 'symphony' and music, they look like a huge vertical xylophone or stacked pipes of sound.
This is columnar basalt, as remarked - Giant's Causeway/Staffa etc, and a few other places in small intrusions. It does not take millions of years, it's the result of an intrusion of lava into the crust - a pipe or flow of lava vertically. The hexagonal structure is caused by cooling and by the crystalling structure of the basalt, which I guess must be a rapid event in geological time, maybe hundreds or thousands of years, not like stalactite formation. Looks like a fantastic good example - better than the Giant's Causeway I think, certainly more dramatic. I like the outcrop near the tree and river.