So my first reaction when I heard that the rotating dining room of Nero's Golden House (Domus Aurea), as described by Suetonius (Life of Nero 31.2), had been found, was that of Mary Beard, to wonder if everyone had got carried away again.
But, on studying more closely the Associated Press report (here reposted on CLASSICS-L), and some good photographs, I have come to the conclusion that this is exactly what the archaeologists say it is.
For a start, the location suggests that it's part of Nero's Domus Aurea. The bit of this that tourists visit (when it's safe to be opened, which has been rare in recent years) is on the Oppian Hill, north-east of the Colosseum, the amphitheatre that Vespasian built on the site of the lake that formed the centrepiece of Nero's park.* But it's clear that this is just one part of the complex, a self-standing pavilion above the lake. The Golden House as a whole was probably many inter-linked buildings, and from Suetonius' account ranged from the Palatine Hill, where Domitian later built his palace, which still survives, across to the Esquiline Hill, of which the Oppian is the southern cusp. This new discovery comes from the eastern slopes of the Palatine. It seems pretty likely that a buried high-status building in that area would be part of the Domus Aurea.
Then there's what has actually be found. The chief feature of the room excavated is an enormous round brick-faced pillar, from the top of which buttresses emerge like spokes of a wheel. The pillar has a row of holes, that look like sockets for wooden beams. If that's the case, then this could be an enormous capstan, similar, if much larger, to what the Museum of London has driving their reconstruction of a Roman water wheel. [But see Edit below.]
It's very odd. Why would one need a room with a pillar in like this? To be honest, I find it hard to imagine what this could be for, if not for supporting a rotating platform above. Unfortunately, the photos don't show whether the pillar is bonded in to the floor, but I presume not.
It's certainly a better candidate for Nero's dining room than that previously advanced, the Octagonal Room in the Oppian pavilion. Until now, that's been as good a suggestion as any. But the trouble is, nothing in that room rotates, and one has to assume that there was a rotating false ceiling in the room. That there was a false ceiling seems probable, but that it rotated is not supported in the archaeology. And Suetonius says that the whole of the main dining room rotated, not just the ceiling.
cenationes laqueatae tabulis eburneis versatilibus, ut flores, fistulatis, ut unguenta desuper spargerentur; praecipua cenationum rotunda, quae perpetuo diebus ac noctibus vice mundi circumageretur
The dining rooms had pannelled ceilings, with versatile ivory slats, so that flowers could be showered from above, and pipes, so that the same could be done with perfume. The principal dining room was round, so that it might revolve perpetually, day and night, like the world.
Suetonius seems to be contrasting the ceilings of the other dining rooms with the whole of the main dining room. This would suggest that identifying the Octagonal Room with the main dining room is wrong, as the whole room can't possibly rotate (though it may well have had the ceiling devices Suetonius says the other dining rooms had). This hasn't stopped generations of scholars writing notes correcting Suetonius, and saying that it was only the ceiling that rotated (Robert Graves in his Penguin translation even adds the word 'roof' into Suetonius' text). But, though it is true that, by the time Suetonius wrote, all of the Golden House had been demolished or buried, he was much nearer the events, and in this case I think scholarship is wrong and the ancient source right.
So yes, I believe this one. And it's a fantastic piece of technology.
A final anecdote: a few years back, I was lucky enough to get in the Domus Aurea in the brief period between its reopening and its closing again. My partner and I were looking away from the remains of the building, out towards what once would have been the view down to the lake, but is now the under-vault of the Baths of Trajan. My partner asked me where the earth had come from that now filled Trajan's substructures. To my surprise, I realized that I was able to answer her. For the Baths of Trajan were built at the same time as the Forum of Trajan was being built a few hundred yards away. And for the latter, a hill was removed, the height of which is indicated by the height of Trajan's column. That earth had to go somewhere, and I think a lot of it must have ended up on top of the Oppian pavilion.
* As an aside, I've always been partial to the suggestion, made I think by Andrew Wallace-Hadrill, that the part of Nero's Golden House was like the Royal Parks of London; owned by the monarch, but an area to which public access was granted by the grace of that monarch, rather than shut off from all public use.
Edit: I should say that I thinking aloud here. And also I am not an engineer. So I may not 100% know what I'm talking about. And so the notion of the giant capstan probably doesn't work. Moreover, it's not what the archaeologists are saying, as quoted in a comment on Mary Beard's blog. They are suggesting the the pillar supported a wooden rotating floor, and are waiting to look inside the pillar (presumably hoping to find that it acted as a sheath for the mechanism). I still think they've found what they say they've found.