The colored marble used in this floor came from many different parts of the Roman Empire, to show that the Senate controlled so many different places and was very powerful. The reddish-purple stone is porphyry (POUR-fir-ee) from Egypt, and the yellow marble is from Nubia, south of Egypt (modern Ethiopia). The green marble (serpentine) is from Asia Minor (modern Turkey).
 

The Senate house also had great big bronze doors on it. (Today those doors have been moved to a church in Rome, but they're still the same doors).

The Senate met in this building for another 300 years after it was built, but with Roman government moved to Constantinople the Senate gradually stopped meeting (the last recorded meeting was in 580 AD). The Senate house is still in pretty good shape today, with a roof on it, because, like the Pantheon, the emperor Phocas gave it to the Popes to turn into a Christian church in the early 600's AD and the Popes took good care of it.