The ancient Romans were famous for their advanced engineering accomplishments. Technology for bringing running water into cities was developed in the east, but transformed by the Romans into a technology inconceivable in Greece. The architecture used in Rome was strongly influenced by Greek and Etruscan sources. Roads Roads were common at that time, but the Romans improved their design and perfected the construction to the extent that many of their roads are still in use today. Their accomplishments surpassed most other civilizations of their time, and after their time, and many of their structures have withstood the test of time to inspire others, especially during the Renaissance. Moreover, their contributions were described in some detail by authors such as Pliny the Elder, so there is a printed record of their many inventions and achievements. Aqueducts A thousand cubic metres (260,000 US gal) of water were brought into Rome by eleven different aqueducts each day. Per capita water usage in ancient Rome matched that of modern-day cities like New York City or modern Rome. Most water was for public use, such as baths and sewers. De aquaeductu is the definitive two volume treatise on 1st century aqueducts of Rome, written by Frontinus. The aqueducts could stretch from long, and typically descended from an elevation of above sea level at the source, to when they reached the reservoirs around the city. Roman engineers used inverted siphons to move water across a valley if they judged it impractical to build a raised aqueduct. The Roman legions were largely responsible for building the aqueducts. Maintenance was often done by slaves. The Romans were among the first civilizations to harness the power of water. They built some of the first watermills outside of Greece for grinding flour and spread the technology for constructing watermills throughout the Mediterranean region. A famous example occurs at Barbegal in southern France, where no fewer than 16 overshot mills built into the side of a hill were worked by a single aqueduct, the outlet from one feeding the mill below in a cascade. They were also skilled in mining, building aqueducts needed to supply equipment used in extracting metal ores, e.g. hydraulic mining, and the building of reservoirs to hold the water needed at the minehead. It is known that they were also capable of building and operating mining equipment such as crushing mills and dewatering machines. Large diameter vertical