jent103, Thanks for the info and I found out what it is.
I have seen the stone blocks without the bronze fitting and always assumed that the wooden capstan post just rotated in the hole.

Day 3 Photos; NUMBERS
http://www.bbc.co.uk/history/ancient...sseum_01.shtml explains the capstan/elevator operation.

The stone is a travertine anchor block set into the concrete floor of the hypogeum (arena's cellar).
The bottom of a wooden capstan fit into this hole in the stone that housed this bronze fixture that was set in lead.
There were 60 capstans in the cellar and this number VIII is one of the few to survive.

I assume the next 2 is what the guide said?

Photo; GLADIATOR BENCHES
That room is clearly a latrine besides the drainage channel beneath the missing marble seats (very likely scavenged when the hypogeum fell into disuse) the center platform almost surely held water basins for the sponge-sticks.
And the water was likely piped-in thru the bottom of the basins.


Photo; NAUMACHIA
Just a simple drainage channel.
The arena is a bowl with a basement that would flood after a major rainstorm.
Plus the Colosseum has water supplied from the Aqua Claudia that reaches to the 2nd seating level and it very likely drains into the basement's drainage channels.
Capua's amphitheater has the same type of hypogeum drains.
If there ever was a Naumachia held in the Colosseum (I believe there was) it was only done in the very early years under Emperor Titus (79-81AD) before any building in or of the hypogeum (it was very likely just a concrete hole).
If any special water suppling pipes/inlets were used it would have been temporary and never used again.


Photo; TEMPLE OF CASTOR AND POLLUX
You accidently mislabed those 2 photos:).
Those 3 columns belong to the Temple of Venus Genetrix (universal mother) in the Forum of Caesar.
Julius Caesar's family claimed that they were descented from that goddess.
Caesar had a gold statue of Cleopatra in the temple which I'm sure thrilled his wife (they live ~250m away:(.


Photo; ONLY IN ROME (Day 1)
That is the Stadium of Domitian which the Piazza Navona is built over:). The present day piazza is over the 'playing field', its original
purpose was for athletic contests in the Greek style (nude) which the Romans really never took to so it was used for other events like public executions which I'm sure packed the Romans in:). The buildings surrounding the piazza (U shaped-the southend is open) are built over the 2 levels of the stadium seats (30,000).
That photo shows one of the many arched arcades, a notorious hang-out for prostitutes of both sexes.
Thanks Again!...Regards, Walter