his activists' group is called “kinta valley watch.”hey explore the caves within the mountains and hills, which are disappearing at an ever-faster rate. ah tat's home, the kinta valley, is located on the malay peninsula in the state of perak. tin deposits were found here long ago. but limestone, granite, and marble can be excavated much more easily. ah: i want to understand what's happening here. i want to find out what's special about these hills. in recent years, we've neglected them and all they contain. reporter: that's why ah tat is now exploring the caves under the hills. today, he's showing an archaeologist an important discovery. there are also prehistoric paintings on the limestone hills. some images are more than 10,000 years old. they are unrivalled in malaysia in terms of the nuanced picture they paint of everyday life. saw: if a quarry occurs at a site that we have never investigated before, there is a possibility that a rock art site was there and then destroyed. because from what we observed so far, rock art is distribute