In order to study the freeze-thaw durability of some ancient concrete samples, 4 samples were tested (2 from Rome and 2 from the Mayans in Mexico) along with a reference sample of present day concrete. Under freeze-thaw conditions both Roman concretes virtually disintegrated after 18 and 29 cycles respectively. Of interest is the Maya concrete from Mexico. Although the Mayans do not receive the attention that the Romans do for their achievements in construction, their concrete is remarkably durable. WHAT DID THE ROMANS ACCOMPLISH WITH CONCRETE? During the 600 years of Roman domination, the Romans discovered and developed a variety of pozzolans throughout their empire. By using pumice, a natural lightweight aggregate, the Romans were the first to create lightweight concrete. Mile-long arched aqueducts were built without expansion joints. Even this brief survey of Roman technological and design advances should persuade us that, in fact, Roman concrete really was good.