Found a case in Rome related to my previous post elsewhere in RAT years ago, about possible multiple finished wall layers in some houses in Pompeii: with one or more fine textured, frescoed or painted plaster layers that rest upon the original fine textured, frescoed or painted plaster layer (that rests on the entire, original medium texture middle plaster layer and the coarse texture base plaster layer on the base stone, brick, and/or concrete wall).
The church of Santa Maria Antiqua, Rome, Italy, has seven layers over three or four centuries:
http://www.archeorm.arti.beniculturali. ... raphy.html
Very interesting.
This website's contents provide a good overview of how much is still left after about 13 to 15 centuries, and of how much has been lost during only the last one century.
Similar cases in every century back to before Rome's 5th century "fall."
Seems some things are better left untouched until we can take proper care of them, and until we are also fully willing to take proper care of them in perpetuity. And if accidentally discovered and touched, they can be re-covered and protected, as has been done with a good number of archeological sites.