Erosional caves in hard rocks

[Yora]

I am pretty familar with limestone rocks, having even been to a couple myself and there are lots of great pictures of them.
But I am also curious about caves that can be found high up in mountains. Apparently they do exist and are not particularly uncommon. But since they are in more out of way places and don't have stalagtites and so on, they don't appear to get much attention. I was trying to find some information about their formation and what it is like inside them, but I can't even find any decent pictures of how they look. There is much more to be found about glacier caves than these.

Does anyone know about any decent online resources to get a better picture of what caves in granite and other hard rocks are like and where they can be found?

[Lethologica]

Mountain granite caves may also be less discussed because they are generally smaller and more rare than limestone caves.

Some discussion of granite cave types and genesis can be found here, with examples pictured. TL;DR: at least for the caves examined, most of them are formed by heavy mechanical weathering causing fractures and joints in the rock, eventually leading to large cuboid slabs breaking away and rolling downhill. The slabs can pile up and form a cave, or they can get stuck between two cliffs Emperor's-New-Groove style and form a cave, or the space they leave behind can become a cave. Some granite caves, on the other hand, appear to originate with cooling magma leaving pockets of vapors and other gases; unlike the slab caves, these are rounder, practically bubble-shaped. These 'miarolitic' caves are small, particularly rare, and not necessarily well-understood.