Our cultural heritage made of stone has in many parts of the world seen to be deteriorating during the last century. There is a debate about the reasons for the breakdown. Is it mainly natural, or is it induced by man? Little is also known about how fast the deterioration is. In Sweden the Bronze Age rock carvings have been of greatest interest. Downwearing rates at more than 20 rock carving sites have been measured with repeated laser scanning during a 10 year long period. The sites and the micro-weathering processes are described in the work, as well as calculations of rock surface roughness. There is a great variation in how well the rock carvings are preserved at different places. Sometimes they are in an excellent state, while they at other places clearly are under destruction. Although average downwearing rates are not faster than on Swedish Precambrian rocks in general they are in many cases fast enough to obscure the ancient rock art and to make this important cultural heritage to disappear. The book is of value for all those who are working and studying ancient monuments and buildings made of stone, regardless of what their main academic subject is.