After a climb up some rather steep stairs (the purpose of which was to slow the flow of patrons coming in so that their tickets could be checked while still allowing a speedy exit after the show; accessibility wasn't a big thing in the Roman era), we came across a row of marble busts that have been found around the Colosseum site.
These are in fact well lit by natural light, but I didn't feel that to be quite dramatic enough so I will admit that I monkeyed around with a spotlight filter here.
The first fully visible head is of a woman, and was carved from Luna marble. No, not from the moon but rather the town which was up near what is today Liguria on the west coast. It's most likely a figure of a goddess (probably Venus or Diana) and dates from the late 1st to early second century AD. It was found during excavations of the Colosseum in 2008.
The next is the head of Asclepius, originally a field surgeon at the siege of Troy in the Iliad, but who was later regarded as a demi-god. Specifically, he was said to be the son of Apollo who was, it's sometimes forgotten, not merely the sun god but also the god of healing. This one was in Thasian marble (from the island of Thasos in the northern Aegean) and dates from the late 2nd/early third century. It was found during the 1995 to 1996 excavations at the Colosseum.
The next one is quite obscured in this shot but fear not, he has his own front on shot later in the Gallery. The rendering of this one was fairly realistic in the sense that the deep-set eyes and thin, set lips are hardly idealised. This suggests that it was a portrait head rather than of a God or an Emperor. Like the previous one, this one dates from the late 2nd to early third century CE.
The final one is the head of a satyr. This one, which is also made of Luna marble, dates from the time of Hadrian. It was found during excavations of the Piazza del Colosseo in 2008.