Now this is cool:

Ancient Roman Concrete Is About to Revolutionize Modern Architecture

After 2,000 years, a long-lost secret behind the creation of one of the world’s most durable man-made creations ever—Roman concrete—has finally been discovered by an international team of scientists, and it may have a significant impact on how we build cities of the future.

The researchers now know why ancient Roman concrete is so superior. They extracted from the floor of Italy’s Pozzuoili Bay, in the northern tip of the Bay of Naples, a sample of concrete headwater that dates back to 37 B.C. and analyzed its mineral components at research labs in Europe and the U.S., including at Berkeley Lab’s Advanced Light Source. The analysis, the scientists believe, reveals the lost recipe of Roman concrete, and it also points to how much more stable and less environmentally damaging it is than today’s blend.