When travelling you will come across both natural and culturally significant areas. Help preserve them and let other people discover them the same way you did. Never interfere with Aboriginal engravings, painting or sites, it is not only offensive to the people but it is also illegal. Other cultural icons such as huts, ruins and mines should also be preserved.
At some point in time things that people do and build in the past becomes of value to the current society. Even if you do not find value in such things it is important to respect that other people. So by avoiding damaging heritage items you can preserve these things for people to experience for years to some.