Several factors aided the process of Romanization: Although Roman influence had a major impact on existing cities in the peninsula, the largest urban development effort focused on newly constructed cities: Tarraco (modern Tarragona), Emerita Augusta (now Mérida) and Italica (in the present day Santiponce, near Seville).
The planners decided the space needed for the houses, plazas and temples, the volume of water required and the number and width of streets.
Tarraco had its origin in the Roman military camp established by the two brothers, consular,[clarification needed] Gnaeus and Publius Cornelius Scipio in 218 BC, when commanding the landing on the Iberian Peninsula during the Second Punic War.
In the year 44 BC, the city received the title of colony under the name Colonia Urbs Iulia Nova Carthago (CVINC), founded by citizens of Roman law.
The military works were the first type of infrastructure built by the Romans in Hispania, due to the confrontation with the Carthaginians on the peninsula during the Second Punic War.
There are notable present-day remains of Roman walls in Zaragoza, Lugo, León, Tarragona, Astorga, Córdoba, Segóbriga and Barcelona.
In addition, any city of at least average importance had a sewer system for the drainage of waste water and to prevent rain flooding the streets.
Roman bridges, an essential complement to the roads, allowed them to overcome the obstacle posed by rivers, which in the case of the Iberian Peninsula can be very wide.
Rome also built a large number of wooden bridges on minor crossings, but today the only surviving references are those made of stone.
The slenderness of this type of construction, along with the tremendous height reached by some of them, makes them the most beautiful works of civil engineering of all time, especially taking into account the difficulties overcome to build them.
The hot springs or public baths became meeting places for people from all walks of life, and their use was encouraged by the authorities, which sometimes covered their expenses which allowed free access to the population.
In the Iberian Peninsula there is great diversity of such archaeological buildings, highlighting their conservation status such as the Baths of Alange near Mérida which, after several restorations over the 18th and 19th centuries, are now open the public as part of a medicinal water spa.
Under the floor of this room was a series of pipes through which hot water circulated, or in smaller bathhouses they used a more residential style of hypocaust heating.
Generally, the spa is surrounded by gardens and other accessory buildings with services for visitors such as gymnasiums, libraries or other places of assembly (laconium), all with the aim of providing customers with a pleasant and invigorating environment.
In other cities like León (founded as a camp of the Legio VII Gemina) are vestiges of these infrastructures and serve as an example on rainy days of a perfect drainage system to prevent flooded streets .
It is however true that very soon assimilated the characteristics of ancient Greek tragedy and comedy.The theater was one of the favorite leisure activities of the Hispanic-Roman, and as with other buildings of public interest, any city of renown could do without owning one.
So much so that the theater of Emerita Augusta was built almost at the same time as the rest of the city by the consul Marcus Agrippa, son in law of the emperor Octavian Augustus.
The Roman theatre had more important activities than comedies or dramas; it was a venue for celebrations that praised the emperor, it is therefore of a more political, not leisurely nature, although on occasion it may have accommodated all kinds of cultural exhibitions.
Its construction in a city where only houses have been found only within the fortress, suggests the importance of this civil building: to represent the political force of the emperor.
The system of slavery made it possible for a man to lose his status as free for various reasons such as: crime, debt or military defeat.
After losing their rights, they were coerced into participating in a form of entertainment which today could be considered excessively brutal, but which at that time was one of the most powerful attractions of urban life: gladiatorial combat.
These arenas would also be witnesses from the 1st century onwards, of brutal repression at certain times which was exerted against the growing Christian population by the Roman authorities.
Undoubtedly, the Colosseum in Rome is the best known and most monumental amphitheater in the world, but within Hispania, several were built whose remains have been preserved, such as Italica, Jerez, Tarragona and Mérida.
Many Iberian tribes were initially aggressive, opposing Roman dominion militarily, though others became allied or tributary entities increasingly reliant on Rome.
The expansion of Roman citizenship in the Antonine Constitution in 212 AD radically changed the concept of romanitas and aided in the further assimilation of native Iberian cultures.