Green roofed structures date back thousands of years, even before the concept of housing as it is known today was birthed. The earliest green roofs came in the form of sod roofs above caves. Plants were used on top of the caves for ceremonial and agricultural purposes. Over time, sod roofs lost their value due to natural disasters and borrowing by animals.  Continue reading below Our Featured Videos The most famous green roof of all time was the Hanging Gardens of Babylon. The gardens were documented as one of the seven wonders of the world at the time. Although similar to what a green roof looks like today, the engineering was quite different. The gardens were built over arched stones overlaid with waterproof reeds with thick tar. Related: Green roofs cover this sustainable school in Prague As modernity kicked in, most people switched to iron sheets, shingles and roofing tiles, among other options. With these options available, a few considered the idea of green roofing.…