Roman architecture was influenced by the cultures they conquered, including the practical functionalism of early Italian cultures, the urban planning of the Etruscans, and the art, philosophy and literature of the Greeks. Roman architecture is characterized by monumentality, technical advances, and integration of beauty with practicality. Buildings were constructed with various vaulting techniques and durable materials like stone, concrete and brick. Roman cities had defined urban plans centered around forums and crossed by main roads, and included infrastructure like aqueducts, bridges and harbors. Major building types included temples, basilicas, baths, theatres, amphitheatres and circuses.