In the year 2007, the Colosseum was ranked among the new seven wonders of the world. It represents a great work of architecture and engineering and it is the symbol of Rome and the city’s magnificent history.In 80 a.C., Emperor Tito inaugurated the Flavio Amphitheater which was later called Colosseum for the colossal statue standing close to it. The building of the Colosseum had started under the reign of Emperor Vespasiano. Its imposing and elegant conception, characterized by its elliptical plant and 188 mt. long and 156 mt. wide  axes, is shaped by means of superimposed arcades, opened on their external side. The three kinds of arcades are surmounted by a podium on which stands an attic decorated with pilasters. The Colosseum was built using brick masonry and calcestruzzo. The grandiose building, as it can be admired today, has been restored and partially reconstructed several times. It was, in the days of the Empire, entirely covered with travertine stone slabs and Tivoli stones, which were unmounted during the Renaissance to adorn some of Rome’s prestigious palaces.The Colosseum was the set of the most important shows in Rome, like gladiatorial contests and fights between gladiators and ferocious beasts. The beasts were made to enter the arena by underground tunnels, through ramps and lifting platforms. The arena was also used as the set for re-enactments of naval battles, the so called “naumachias”; on those occasions a special large basin of water and a fantastic scenery were created.