Besides searching for the topic, Natural Places, what are other terms you can search for? What are some broader terms, narrower terms, or related terms? Think of words from any readings you have done so far, or take a look at Wikipedia or in Credo Reference for some context.
Not all authors use the same language to describe similar topics, so you will need to try a variety of searches in databases.
Example: What are the interpretations of paleolithic art?