Ancient Roman architecture
Although concrete had been used on a minor scale in Mesopotamia, Roman architects perfected Roman concrete and used it in buildings where it could stand on its own and support a great deal of weight. The first use of concrete by the Romans was in the town of Cosa sometime after 273 BC. Ancient Roman concrete was a mixture of lime mortar, aggregate, pozzolana, water, and stones, and was stronger than previously-used concretes. The ancient builders placed these ingredients in wooden frames where they hardened and bonded to a facing of stones or (more frequently) bricks. The aggregates used were often much larger than in modern concrete, amounting to rubble.
Pepper Pot, Brighton
The main building material was said to be cement by English Heritage in its listing description, but research undertaken during the 2011 restoration work discovered that the core of the Pepper Pot is made of a pioneering type of concrete known as "Ranger's Artificial Stone" or "Ranger's Lime Concrete"—making it one of the oldest buildings in England to use this material. William Ranger, a builder from the nearby village of Ringmer, invented this in the early 19th century.