The construction of the Colosseum was financed by booty from the Jewish War waged by emperor Vespasian and his sons Titus and Domitian.
Before the overgrowth of vegetation was cleared away in 1871 over 400 species of plants grew on the ruins, a variety made possible both by the seeds ingested by exotic animals supplied for the games and the amphitheater’s special microclimate.
The Colosseum was covered with a giant sail known as the velarium. This protected the spectators from the sun and rain. It was attached to large poles on top of the Colosseum and anchored to the ground by large ropes.
Large sections of the Roman Colosseum as it now stands are not ancient at all, but the result of restoration in the 19th century. Only 1/3 of the original amphitheater remains intact. 2/3 is gone forever, especially the south side. Its original marble facing, the statues decorating the arches and the lavish decoration of the interior did not survive.
On visiting the real Colosseum, film director Ridley Scott remarked to production designer Arthur Max that it was “too small” for the movie Gladiator so they designed an outsized “Rome of the imagination”.