According to the hermetic Law of Analogy, because we individuals have chakras, larger systems that are analogous to us also have chakras. Thus, countries have chakras. The Earth has chakras. Hell, the universe probably has chakras.
Each of the chakras contain megaliths, temples, religious structures, or monuments.
This tells us that our ancestors knew about the spiritual power that exists within these energy centers, and thought to harness it by building their places of worship along them.