Acid rain most often damages stone architecture by causing

It's often caused by loss of carved detail.

Scraping and dissolving the stone architecture

Explanation:

Acid rain reacts with the constituent elements of the stone/masonry structure there by creating cracks in the structure. These cracks weaken the rock and thus leads to scarping of the loosen part. This destroys the design and built of the structure. The cracks formed becomes a source of weak faults from where the rock structure starts disintegrating and in case rain also occur the water forces the structure to dissolve.