appearances. The Romans absorbed Greek influence, apparent in many aspects closely related to architecture; for example, this can be seen in the introduction and use of the Triclinium in Roman villas as a place and manner of dining. The Romans, similarly, were indebted to their Etruscan neighbors and forefathers who supplied them with a wealth of knowledge essential for future architectural solutions,[citation needed] such as hydraulics and in the construction of arches.Social elements such as wealth and high population densities in cities forced the ancient Romans to discover new (architectural) solutions of their own. The use of vaults and arches together with a sound knowledge of building materials, for example, enabled them to achieve unprecedented successes in the construction of imposing structures for public use. Examples include the aqueducts of Rome, the Baths of Diocletian and the Baths of Caracalla, the basilicas and perhaps most famously of all, the Colosseum. They were reproduced at smaller scale in most important towns and cities in the Empire. Some surviving structures are almost complete, such as the town walls of Lugo in Hispania Tarraconensis, or northern Spain.
Political propaganda demanded that these buildings should be made to impress as well as perform a public function.[citation needed] The Romans didn't feel restricted by Greek aesthetic axioms alone in order to achieve these objectives.[citation needed] The Pantheon is a supreme example of this, particularly in the version rebuilt by Hadrian and which still stands in its celestial glory as a prototype of several other great buildings of Eastern architecture. The same emperor left his mark on the landscape of northern Britain when he built a wall to mark the limits of the empire, and after further conquests in Scotland, the Antonine wall was built to replace Hadrian's Wall.
